LeetCode 11xx

LeetCode problems 1100–1199

100 items

LeetCode 11xx

# Problem Difficulty Time Notes
1100 Find K-Length Substrings With No Repeated Characters 🟡 Medium 57s The problem asks us to count how many substrings of length k contai…
1101 The Earliest Moment When Everyone Become Friends 🟡 Medium 5m 31s The problem is asking us to determine the earliest time at which a …
1102 Path With Maximum Minimum Value 🟡 Medium 1m 55s The problem asks us to find the maximum possible score of a path fr…
1103 Distribute Candies to People 🟢 Easy 6m 19s The problem describes a sequential candy distribution process acros…
1104 Path In Zigzag Labelled Binary Tree 🟡 Medium 1m 9s This problem describes an infinite binary tree where nodes are norm…
1105 Filling Bookcase Shelves 🟡 Medium 57s The problem asks us to arrange a sequence of books on a bookshelf w…
1106 Parsing A Boolean Expression 🔴 Hard 48s The problem asks us to evaluate a boolean expression represented as…
1107 New Users Daily Count 🟡 Medium 1m 18s We are given a database table called Traffic that records different…
1108 Defanging an IP Address 🟢 Easy 51s The problem asks us to transform a valid IPv4 address into its "def…
1109 Corporate Flight Bookings 🟡 Medium 52s The problem is asking us to compute the total number of seats reser…
1110 Delete Nodes And Return Forest 🟡 Medium 1m 23s This problem gives us the root of a binary tree and a list of node …
1111 Maximum Nesting Depth of Two Valid Parentheses Strings 🟡 Medium 47s The problem asks us to take a valid parentheses string seq and spli…
1112 Highest Grade For Each Student 🟡 Medium 1m 8s The problem gives us a database table named Enrollments. Each row r…
1113 Reported Posts 🟢 Easy 51s The problem is asking us to determine the number of posts that were…
1114 Print in Order 🟢 Easy 1m 20s This problem asks us to coordinate three independent threads so tha…
1115 Print FooBar Alternately 🟡 Medium 1m 6s This problem is a classic concurrency synchronization task. We are …
1116 Print Zero Even Odd 🟡 Medium 46s The problem requires us to implement a multithreaded class ZeroEven…
1117 Building H2O 🟡 Medium 1m 7s This problem asks us to coordinate multiple concurrent threads so t…
1118 Number of Days in a Month 🟢 Easy 40s The problem asks us to determine the number of days in a specific m…
1119 Remove Vowels from a String 🟢 Easy 45s The problem asks us to remove vowels from a given string s. Specifi…
1120 Maximum Average Subtree 🟡 Medium 1m 5s This problem asks us to find the maximum average value among all su…
1121 Divide Array Into Increasing Sequences 🔴 Hard 39s The problem asks us to determine if a sorted integer array nums can…
1122 Relative Sort Array 🟢 Easy 1m 2s This problem asks us to sort arr1, but not in ordinary ascending or…
1123 Lowest Common Ancestor of Deepest Leaves 🟡 Medium 1m 13s This problem asks us to find the lowest common ancestor, abbreviate…
1124 Longest Well-Performing Interval 🟡 Medium 1m 22s Edit The problem gives us an array hours, where each element repres…
1125 Smallest Sufficient Team 🔴 Hard 1m 12s This problem asks us to build the smallest possible team that colle…
1126 Active Businesses 🟡 Medium 1m 15s The problem gives us a database table named Events. Each row repres…
1127 User Purchase Platform 🔴 Hard 3m 27s The Spending table records purchases made by users on an e-commerce…
1128 Number of Equivalent Domino Pairs 🟢 Easy 46s The problem is asking us to count all pairs of dominoes in a list t…
1129 Shortest Path with Alternating Colors 🟡 Medium 2m 3s The problem gives us a directed graph with n nodes labeled from 0 t…
1130 Minimum Cost Tree From Leaf Values 🟡 Medium 45s The problem asks us to construct a binary tree from an input array …
1131 Maximum of Absolute Value Expression 🟡 Medium 1m 10s The problem gives us two integer arrays, arr1 and arr2, both having…
1132 Reported Posts II 🟡 Medium 48s The problem asks us to calculate the average daily percentage of po…
1133 Largest Unique Number 🟢 Easy 46s The problem is asking us to identify the largest integer in an arra…
1134 Armstrong Number 🟢 Easy 52s In this problem, we are given an integer n, and we must determine w…
1135 Connecting Cities With Minimum Cost 🟡 Medium 1m 23s This problem asks us to connect n cities together using a set of po…
1136 Parallel Courses 🟡 Medium 45s The problem is asking us to determine the minimum number of semeste…
1137 N-th Tribonacci Number 🟢 Easy 1m 28s The problem asks us to compute the n-th number in the Tribonacci se…
1138 Alphabet Board Path 🟡 Medium 1m 8s The problem gives us a special alphabet board and asks us to genera…
1139 Largest 1-Bordered Square 🟡 Medium 38s That is a long, detailed reference document with multiple required …
1140 Stone Game II 🟡 Medium 47s The problem is a two-player turn-based game played on a row of ston…
1141 User Activity for the Past 30 Days I 🟢 Easy 1m 16s This problem asks us to compute the number of distinct active users…
1142 User Activity for the Past 30 Days II 🟢 Easy 53s This problem asks us to compute the average number of sessions per …
1143 Longest Common Subsequence 🟡 Medium 1m 13s The problem asks us to find the length of the longest subsequence t…
1144 Decrease Elements To Make Array Zigzag 🟡 Medium 1m 18s The problem gives an integer array nums and allows only one type of…
1145 Binary Tree Coloring Game 🟡 Medium 2m 37s The problem is a two-player game played on a binary tree, where eac…
1146 Snapshot Array 🟡 Medium 6m 58s The problem asks us to implement a SnapshotArray, a data structure …
1147 Longest Chunked Palindrome Decomposition 🔴 Hard 44s The problem asks us to decompose a given string text into the large…
1148 Article Views I 🟢 Easy 40s The problem is asking us to identify all authors who have viewed at…
1149 Article Views II 🟡 Medium 1m 15s The problem gives us a database table named Views. Each row represe…
1150 Check If a Number Is Majority Element in a Sorted Array 🟢 Easy 44s This problem asks us to determine if a given target integer is a ma…
1151 Minimum Swaps to Group All 1's Together 🟡 Medium 1m 13s This problem asks us to determine the minimum number of swaps neede…
1152 Analyze User Website Visit Pattern 🟡 Medium 1m 1s Here is a comprehensive, detailed technical solution guide for Leet…
1153 String Transforms Into Another String 🔴 Hard 1m 17s The problem gives us two strings, str1 and str2, which are guarante…
1154 Day of the Year 🟢 Easy 43s The problem asks us to compute the ordinal day number of a year giv…
1155 Number of Dice Rolls With Target Sum 🟡 Medium 1m 41s The problem gives us n identical dice, where each die has faces num…
1156 Swap For Longest Repeated Character Substring 🟡 Medium 48s The problem asks us to determine the length of the longest substrin…
1157 Online Majority Element In Subarray 🔴 Hard 41s The problem asks us to design a data structure that can efficiently…
1158 Market Analysis I 🟡 Medium 1m 25s This problem asks us to analyze purchasing activity on an online sh…
1159 Market Analysis II 🔴 Hard 1m 5s This problem asks us to determine, for every user in the marketplac…
1160 Find Words That Can Be Formed by Characters 🟢 Easy 1m 7s This problem asks us to determine which words from a given list can…
1161 Maximum Level Sum of a Binary Tree 🟡 Medium 1m 24s In this problem, we are given the root node of a binary tree. Every…
1162 As Far from Land as Possible 🟡 Medium 1m 15s The problem requires finding the water cell in a given n x n grid t…
1163 Last Substring in Lexicographical Order 🔴 Hard 1m 11s The problem asks us to find the substring of a given string s that …
1164 Product Price at a Given Date 🟡 Medium 1m 19s The problem provides a database table named Products, where each ro…
1165 Single-Row Keyboard 🟢 Easy 52s The problem describes a single-row keyboard where each key is posit…
1166 Design File System 🟡 Medium 1m 14s This problem asks us to design a simplified file system that suppor…
1167 Minimum Cost to Connect Sticks 🟡 Medium 1m 16s The problem gives us an array of positive integers called sticks, w…
1168 Optimize Water Distribution in a Village 🔴 Hard 45s The problem asks us to supply water to all houses in a village in t…
1169 Invalid Transactions 🟡 Medium 1m 14s The problem asks us to identify transactions that are potentially i…
1170 Compare Strings by Frequency of the Smallest Character 🟡 Medium 1m 32s The problem defines a function f(s) for a non-empty string s. This …
1171 Remove Zero Sum Consecutive Nodes from Linked List 🟡 Medium 47s The problem requires us to repeatedly remove consecutive nodes in a…
1172 Dinner Plate Stacks 🔴 Hard 1m 44s The problem asks us to design a data structure that behaves like an…
1173 Immediate Food Delivery I 🟢 Easy 41s The problem is asking to calculate the percentage of immediate food…
1174 Immediate Food Delivery II 🟡 Medium 1m 21s The problem provides a Delivery table that records food delivery or…
1175 Prime Arrangements 🟢 Easy 48s The problem asks us to count how many permutations of numbers from …
1176 Diet Plan Performance 🟢 Easy 40s The problem is asking us to simulate a dieter’s performance over a …
1177 Can Make Palindrome from Substring 🟡 Medium 44s The problem asks us to determine whether certain substrings of a gi…
1178 Number of Valid Words for Each Puzzle 🔴 Hard 1m 27s The problem asks us to determine, for each given puzzle string, how…
1179 Reformat Department Table 🟢 Easy 43s The problem is asking us to take a table Department that records re…
1180 Count Substrings with Only One Distinct Letter 🟢 Easy 1m 17s The problem asks us to count how many substrings of a given string …
1181 Before and After Puzzle 🟡 Medium 1m 20s The problem gives us an array of phrases, where each phrase is a st…
1182 Shortest Distance to Target Color 🟡 Medium 1m 11s The problem gives us an array called colors, where each position co…
1183 Maximum Number of Ones 🔴 Hard 1m 23s The problem gives us a binary matrix M with dimensions height x wid…
1184 Distance Between Bus Stops 🟢 Easy 1m 8s In this problem, we are given a circular bus route with n stops num…
1185 Day of the Week 🟢 Easy 1m 11s This problem asks us to determine which day of the week corresponds…
1186 Maximum Subarray Sum with One Deletion 🟡 Medium 51s The problem is asking us to find the maximum sum of a contiguous su…
1187 Make Array Strictly Increasing 🔴 Hard 40s The problem is asking us to transform the array arr1 into a strictl…
1188 Design Bounded Blocking Queue 🟡 Medium 1m 8s This problem asks us to implement a thread-safe bounded blocking qu…
1189 Maximum Number of Balloons 🟢 Easy 46s The problem asks us to determine the maximum number of times the wo…
1190 Reverse Substrings Between Each Pair of Parentheses 🟡 Medium 1m 15s The problem gives us a string s containing lowercase English letter…
1191 K-Concatenation Maximum Sum 🟡 Medium 1m 41s This problem asks us to find the maximum possible sum of a contiguo…
1192 Critical Connections in a Network 🔴 Hard 1m 31s This problem gives us an undirected graph representing a network of…
1193 Monthly Transactions I 🟡 Medium 47s The problem is asking us to produce aggregated statistics on transa…
1194 Tournament Winners 🔴 Hard 44s The problem asks us to determine the winner in each group of player…
1195 Fizz Buzz Multithreaded 🟡 Medium 1m 24s The problem asks us to coordinate four separate threads so they col…
1196 How Many Apples Can You Put into the Basket 🟢 Easy 36s This problem is asking us to determine how many apples we can fit i…
1197 Minimum Knight Moves 🟡 Medium 49s This problem asks us to compute the minimum number of moves a knigh…
1198 Find Smallest Common Element in All Rows 🟡 Medium 1m 4s The problem asks us to find the smallest element that appears in ev…
1199 Minimum Time to Build Blocks 🔴 Hard 1m 43s The problem requires determining the minimum amount of time to buil…
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LeetCode 1100 - Find K-Length Substrings With No Repeated Characters

The problem asks us to count how many substrings of length k contain only unique characters. A substring is a contiguous portion of the string. For every possible substring of length k, we must determine whether all characters inside it are distinct.
leetcode Medium hash-table string sliding-window May 28, 2026
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LeetCode 1101 - The Earliest Moment When Everyone Become Friends

The problem is asking us to determine the earliest time at which a group of n people all become mutually acquainted, given a sequence of friendship formation events with timestamps.
leetcode Medium array union-find sorting May 28, 2026
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LeetCode 1102 - Path With Maximum Minimum Value

The problem asks us to find the maximum possible score of a path from the top-left corner (0, 0) to the bottom-right corner (m-1, n-1) of a 2D grid. Each cell in the grid contains an integer value, and the score of a path is defined as the minimum value along that path.
leetcode Medium array binary-search depth-first-search breadth-first-search union-find heap-(priority-queue) matrix May 28, 2026
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LeetCode 1103 - Distribute Candies to People

The problem describes a sequential candy distribution process across a row of people. We are given two integers, candies and numpeople. The goal is to simulate distributing candies in increasing order until all candies are exhausted.
leetcode Easy math simulation May 28, 2026
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LeetCode 1104 - Path In Zigzag Labelled Binary Tree

This problem describes an infinite binary tree where nodes are normally arranged level by level, but with a twist in how labels are assigned. In a standard binary tree, nodes in each level are labeled from left to right.
leetcode Medium math tree binary-tree May 28, 2026
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LeetCode 1105 - Filling Bookcase Shelves

The problem asks us to arrange a sequence of books on a bookshelf with multiple shelves while minimizing the total height of the bookshelf. Each book is described by its thickness and height, and the books must be placed in the given order.
leetcode Medium array dynamic-programming May 28, 2026
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LeetCode 1106 - Parsing A Boolean Expression

The problem asks us to evaluate a boolean expression represented as a string. The expression can contain the literals 't' and 'f' for true and false, as well as three types of operators: logical NOT '!', logical AND '&', and logical OR ''. Each operator has a specific syntax: '!
leetcode Hard string stack recursion May 28, 2026
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LeetCode 1107 - New Users Daily Count

We are given a database table called Traffic that records different user activities on different dates. Each row contains a userid, an activity type, and an activitydate.
leetcode Medium database May 28, 2026
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LeetCode 1108 - Defanging an IP Address

The problem asks us to transform a valid IPv4 address into its "defanged" version. A defanged IP address is created by replacing every period character "." with the string "[.]". An IPv4 address consists of four numeric segments separated by periods. For example, "1.1.1.
leetcode Easy string May 28, 2026
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LeetCode 1109 - Corporate Flight Bookings

The problem is asking us to compute the total number of seats reserved for each flight given a list of flight bookings. Each booking specifies a range of consecutive flights [firsti, lasti] and the number of seats seatsi reserved for each flight in that range.
leetcode Medium array prefix-sum May 28, 2026
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LeetCode 1110 - Delete Nodes And Return Forest

This problem gives us the root of a binary tree and a list of node values that must be deleted from the tree. Every node value in the tree is unique, which is important because it means we can identify nodes directly by value without ambiguity.
leetcode Medium array hash-table tree depth-first-search binary-tree May 28, 2026
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LeetCode 1111 - Maximum Nesting Depth of Two Valid Parentheses Strings

The problem asks us to take a valid parentheses string seq and split it into two disjoint subsequences A and B such that each subsequence is itself a valid parentheses string (VPS).
leetcode Medium string stack May 28, 2026
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LeetCode 1112 - Highest Grade For Each Student

The problem gives us a database table named Enrollments. Each row represents a student taking a course and receiving a grade for that course.
leetcode Medium database May 28, 2026
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LeetCode 1113 - Reported Posts

The problem is asking us to determine the number of posts that were reported yesterday grouped by the reason for the report.
leetcode Easy database May 28, 2026
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LeetCode 1114 - Print in Order

This problem asks us to coordinate three independent threads so that they execute in a strict order, regardless of how the operating system schedules them. We are given a class with three methods, first(), second(), and third().
leetcode Easy concurrency May 28, 2026
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LeetCode 1115 - Print FooBar Alternately

This problem is a classic concurrency synchronization task. We are given a class FooBar with two methods, foo() and bar().
leetcode Medium concurrency May 28, 2026
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LeetCode 1116 - Print Zero Even Odd

The problem requires us to implement a multithreaded class ZeroEvenOdd that coordinates three separate threads to print numbers in a specific sequence. Thread A prints 0s, Thread B prints even numbers, and Thread C prints odd numbers.
leetcode Medium concurrency May 28, 2026
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LeetCode 1117 - Building H2O

This problem asks us to coordinate multiple concurrent threads so that they form water molecules correctly. A water molecule contains exactly two hydrogen atoms and one oxygen atom, so the synchronization logic must ensure that threads proceed only in groups of three…
leetcode Medium concurrency May 28, 2026
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LeetCode 1118 - Number of Days in a Month

The problem asks us to determine the number of days in a specific month of a given year. The inputs are two integers: year, which ranges from 1583 to 2100, and month, which ranges from 1 (January) to 12 (December).
leetcode Easy math May 28, 2026
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LeetCode 1119 - Remove Vowels from a String

The problem asks us to remove vowels from a given string s. Specifically, the vowels are defined as the lowercase characters 'a', 'e', 'i', 'o', and 'u'. The input string consists only of lowercase English letters, and its length ranges from 1 to 1000.
leetcode Easy string May 28, 2026
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LeetCode 1120 - Maximum Average Subtree

This problem asks us to find the maximum average value among all subtrees of a given binary tree. A subtree is defined as any node along with all of its descendants. The average of a subtree is the sum of its node values divided by the number of nodes in that subtree.
leetcode Medium tree depth-first-search binary-tree May 28, 2026
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LeetCode 1121 - Divide Array Into Increasing Sequences

The problem asks us to determine if a sorted integer array nums can be divided into one or more disjoint increasing subsequences, where each subsequence has a length of at least k.
leetcode Hard array counting May 28, 2026
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LeetCode 1122 - Relative Sort Array

This problem asks us to sort arr1, but not in ordinary ascending or descending order. Instead, the sorting order is partially dictated by another array, arr2. The key requirement is that every number appearing in arr2 must appear in arr1 in exactly the same relative order.
leetcode Easy array hash-table sorting counting-sort May 28, 2026
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LeetCode 1123 - Lowest Common Ancestor of Deepest Leaves

This problem asks us to find the lowest common ancestor, abbreviated as LCA, of all the deepest leaf nodes in a binary tree. A leaf node is any node with no children. The depth of the root is 0, and every level downward increases the depth by 1.
leetcode Medium hash-table tree depth-first-search breadth-first-search binary-tree May 28, 2026
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LeetCode 1124 - Longest Well-Performing Interval

Edit The problem gives us an array hours, where each element represents the number of hours an employee worked on a specific day. A day is classified as tiring if the employee worked strictly more than 8 hours. Otherwise, the day is considered non-tiring.
leetcode Medium array hash-table stack monotonic-stack prefix-sum May 28, 2026
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LeetCode 1125 - Smallest Sufficient Team

This problem asks us to build the smallest possible team that collectively covers every required skill. We are given two inputs: - reqskills, a list of unique required skills - people, where people[i] contains the skills possessed by person i A team is considered sufficient if…
leetcode Hard array dynamic-programming bit-manipulation bitmask May 28, 2026
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LeetCode 1126 - Active Businesses

The problem gives us a database table named Events. Each row represents how many times a certain type of event occurred for a particular business.
leetcode Medium database May 28, 2026
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LeetCode 1127 - User Purchase Platform

The Spending table records purchases made by users on an e-commerce platform. Every row represents one user's spending on a specific date using either the mobile platform or the desktop platform.
leetcode Hard database May 28, 2026
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LeetCode 1128 - Number of Equivalent Domino Pairs

The problem is asking us to count all pairs of dominoes in a list that are equivalent, where two dominoes [a, b] and [c, d] are considered equivalent if one is a rotation of the other, meaning either (a == c and b == d) or (a == d and b == c).
leetcode Easy array hash-table counting May 28, 2026
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LeetCode 1129 - Shortest Path with Alternating Colors

The problem gives us a directed graph with n nodes labeled from 0 to n - 1. Every edge in the graph has a color, either red or blue.
leetcode Medium breadth-first-search graph-theory May 28, 2026
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LeetCode 1130 - Minimum Cost Tree From Leaf Values

The problem asks us to construct a binary tree from an input array arr of positive integers, where each integer represents a leaf node in an in-order traversal.
leetcode Medium array dynamic-programming stack greedy monotonic-stack May 28, 2026
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LeetCode 1131 - Maximum of Absolute Value Expression

The problem gives us two integer arrays, arr1 and arr2, both having the same length. We must compute the maximum possible value of the following expression across every pair of indices (i, j): The task is not asking for the indices themselves, only the largest achievable value.
leetcode Medium array math May 28, 2026
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LeetCode 1132 - Reported Posts II

The problem asks us to calculate the average daily percentage of posts that were removed after being reported as spam. We are given two tables: Actions and Removals.
leetcode Medium database May 28, 2026
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LeetCode 1133 - Largest Unique Number

The problem is asking us to identify the largest integer in an array that occurs exactly once. In other words, among all integers that are unique (appear only one time), we need to find the maximum. If no such integer exists, the output should be -1.
leetcode Easy array hash-table sorting May 28, 2026
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LeetCode 1134 - Armstrong Number

In this problem, we are given an integer n, and we must determine whether it is an Armstrong number. An Armstrong number is defined as follows: - Let k be the number of digits in n. - Take every digit in the number. - Raise each digit to the power k.
leetcode Easy math May 28, 2026
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LeetCode 1135 - Connecting Cities With Minimum Cost

This problem asks us to connect n cities together using a set of possible bidirectional connections. Each connection has a cost, and our goal is to connect every city while minimizing the total cost.
leetcode Medium union-find graph-theory heap-(priority-queue) minimum-spanning-tree May 28, 2026
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LeetCode 1136 - Parallel Courses

The problem is asking us to determine the minimum number of semesters required to complete n courses given a set of prerequisite relationships.
leetcode Medium graph-theory topological-sort May 28, 2026
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LeetCode 1137 - N-th Tribonacci Number

The problem asks us to compute the n-th number in the Tribonacci sequence. The Tribonacci sequence is very similar to the Fibonacci sequence, except that instead of summing the previous two numbers, each value is formed by summing the previous three numbers.
leetcode Easy math dynamic-programming memoization May 28, 2026
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LeetCode 1138 - Alphabet Board Path

The problem gives us a special alphabet board and asks us to generate the shortest sequence of moves needed to spell a target string. The board contains lowercase English letters arranged in rows: We always begin at position (0, 0), which corresponds to the character 'a'.
leetcode Medium hash-table string May 28, 2026
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LeetCode 1139 - Largest 1-Bordered Square

That is a long, detailed reference document with multiple required sections, complete implementations, worked traces, and test coverage. I can provide the full guide in a single response.
leetcode Medium array dynamic-programming matrix May 28, 2026
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LeetCode 1140 - Stone Game II

The problem is a two-player turn-based game played on a row of stone piles. Each pile has a positive number of stones, and players take turns taking stones from the start of the remaining piles.
leetcode Medium array math dynamic-programming prefix-sum game-theory May 28, 2026
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LeetCode 1141 - User Activity for the Past 30 Days I

This problem asks us to compute the number of distinct active users for each day within a fixed 30 day window. The window ends on 2019-07-27, inclusive, which means we only consider activity dates from 2019-06-28 through 2019-07-27.
leetcode Easy database May 28, 2026
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LeetCode 1142 - User Activity for the Past 30 Days II

This problem asks us to compute the average number of sessions per user over a specific 30-day period ending on 2019-07-27. Each row in the Activity table represents an activity a user performed in a session on a particular date.
leetcode Easy database May 28, 2026
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LeetCode 1143 - Longest Common Subsequence

The problem asks us to find the length of the longest subsequence that appears in both input strings. A subsequence is formed by deleting some characters from a string while keeping the remaining characters in the same relative order. The characters do not need to be contiguous.
leetcode Medium string dynamic-programming May 28, 2026
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LeetCode 1144 - Decrease Elements To Make Array Zigzag

The problem gives an integer array nums and allows only one type of operation, decreasing any element by 1. We may perform this operation as many times as needed on any elements. Our goal is to transform the array into a zigzag array with the minimum number of moves.
leetcode Medium array greedy May 28, 2026
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LeetCode 1145 - Binary Tree Coloring Game

The problem is a two-player game played on a binary tree, where each player colors nodes starting from an initial chosen node. Player 1 picks a node x and colors it red, while Player 2 picks a different node y and colors it blue.
leetcode Medium tree depth-first-search binary-tree May 28, 2026
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LeetCode 1146 - Snapshot Array

The problem asks us to implement a SnapshotArray, a data structure that behaves like an array but also allows taking snapshots of its state at any moment and retrieving the value of any element at a specific snapshot.
leetcode Medium array hash-table binary-search design May 28, 2026
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LeetCode 1147 - Longest Chunked Palindrome Decomposition

The problem asks us to decompose a given string text into the largest possible number of contiguous substrings such that the sequence of substrings forms a palindromic pattern.
leetcode Hard two-pointers string dynamic-programming greedy rolling-hash hash-function May 28, 2026
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LeetCode 1148 - Article Views I

The problem is asking us to identify all authors who have viewed at least one of their own articles. The input is a database table Views that contains information about articles, their authors, the viewers, and the dates on which the articles were viewed.
leetcode Easy database May 28, 2026
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LeetCode 1149 - Article Views II

The problem gives us a database table named Views. Each row represents a single viewing event where a user viewed an article on a specific date.
leetcode Medium database May 28, 2026
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LeetCode 1150 - Check If a Number Is Majority Element in a Sorted Array

This problem asks us to determine if a given target integer is a majority element in a sorted array nums. A majority element is defined as an element that appears more than half of the array's length. In other words, if nums.
leetcode Easy array binary-search May 28, 2026
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LeetCode 1151 - Minimum Swaps to Group All 1's Together

This problem asks us to determine the minimum number of swaps needed to group all 1s in a binary array into one contiguous block. The block can appear anywhere in the array, as long as all 1s end up adjacent.
leetcode Medium array sliding-window May 28, 2026
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LeetCode 1152 - Analyze User Website Visit Pattern

Here is a comprehensive, detailed technical solution guide for LeetCode 1152 - Analyze User Website Visit Pattern following your requested format exactly. The problem asks us to analyze user website visit sequences to determine the most common pattern of length three.
leetcode Medium array hash-table string sorting May 28, 2026
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LeetCode 1153 - String Transforms Into Another String

The problem gives us two strings, str1 and str2, which are guaranteed to have the same length. We want to determine whether it is possible to transform str1 into str2 using a sequence of character conversion operations.
leetcode Hard hash-table string graph-theory May 28, 2026
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LeetCode 1154 - Day of the Year

The problem asks us to compute the ordinal day number of a year given a date in the format YYYY-MM-DD. For example, January 1st is always day 1, January 2nd is day 2, and December 31st is either day 365 or 366 depending on whether the year is a leap year.
leetcode Easy math string May 28, 2026
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LeetCode 1155 - Number of Dice Rolls With Target Sum

The problem gives us n identical dice, where each die has faces numbered from 1 to k. We roll all n dice and want to count how many different sequences of rolls produce a total sum equal to target. The important detail is that order matters.
leetcode Medium dynamic-programming May 28, 2026
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LeetCode 1156 - Swap For Longest Repeated Character Substring

The problem asks us to determine the length of the longest substring in a given string text where all characters are the same, and we are allowed to swap exactly two characters in the string.
leetcode Medium hash-table string sliding-window May 28, 2026
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LeetCode 1157 - Online Majority Element In Subarray

The problem asks us to design a data structure that can efficiently answer majority element queries on subarrays of a given array.
leetcode Hard array binary-search design binary-indexed-tree segment-tree May 28, 2026
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LeetCode 1158 - Market Analysis I

This problem asks us to analyze purchasing activity on an online shopping platform. We are given three database tables: Users, Orders, and Items.
leetcode Medium database May 28, 2026
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LeetCode 1159 - Market Analysis II

This problem asks us to determine, for every user in the marketplace system, whether the brand of the second item they sold matches their favorite brand. The database contains three tables: - The Users table stores user information, including their favoritebrand.
leetcode Hard database May 28, 2026
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LeetCode 1160 - Find Words That Can Be Formed by Characters

This problem asks us to determine which words from a given list can be constructed using the characters available in another string, chars. A word is considered good if every character it needs exists in chars in sufficient quantity.
leetcode Easy array hash-table string counting May 28, 2026
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LeetCode 1161 - Maximum Level Sum of a Binary Tree

In this problem, we are given the root node of a binary tree. Every node belongs to a specific level in the tree. The root is at level 1, its direct children are at level 2, their children are at level 3, and so on.
leetcode Medium tree depth-first-search breadth-first-search binary-tree May 28, 2026
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LeetCode 1162 - As Far from Land as Possible

The problem requires finding the water cell in a given n x n grid that is farthest from any land cell, using Manhattan distance. The grid consists only of 0s and 1s, where 0 represents water and 1 represents land.
leetcode Medium array dynamic-programming breadth-first-search matrix May 28, 2026
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LeetCode 1163 - Last Substring in Lexicographical Order

The problem asks us to find the substring of a given string s that is lexicographically largest among all possible substrings. A substring is any contiguous portion of the string.
leetcode Hard two-pointers string May 28, 2026
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LeetCode 1164 - Product Price at a Given Date

The problem provides a database table named Products, where each row represents a price update for a product on a specific date.
leetcode Medium database May 28, 2026
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LeetCode 1165 - Single-Row Keyboard

The problem describes a single-row keyboard where each key is positioned at a unique index from 0 to 25. You are given a string keyboard of length 26 that specifies the layout of all lowercase English letters.
leetcode Easy hash-table string May 28, 2026
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LeetCode 1166 - Design File System

This problem asks us to design a simplified file system that supports two operations: 1. Creating a new path with an associated integer value. 2. Retrieving the value stored at a path. A path behaves similarly to a directory structure in a real operating system.
leetcode Medium hash-table string design trie May 28, 2026
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LeetCode 1167 - Minimum Cost to Connect Sticks

The problem gives us an array of positive integers called sticks, where each value represents the length of a stick. We are allowed to repeatedly connect any two sticks together.
leetcode Medium array greedy heap-(priority-queue) May 28, 2026
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LeetCode 1168 - Optimize Water Distribution in a Village

The problem asks us to supply water to all houses in a village in the most cost-effective way. Each house has two options: either build a well in the house with a fixed cost, or connect the house to another house via pipes, where each pipe has its own construction cost.
leetcode Hard union-find graph-theory heap-(priority-queue) minimum-spanning-tree May 28, 2026
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LeetCode 1169 - Invalid Transactions

The problem asks us to identify transactions that are potentially invalid based on two rules. First, any transaction with an amount greater than $1000 is invalid.
leetcode Medium array hash-table string sorting May 28, 2026
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LeetCode 1170 - Compare Strings by Frequency of the Smallest Character

The problem defines a function f(s) for a non-empty string s. This function returns the frequency of the lexicographically smallest character in the string.
leetcode Medium array hash-table string binary-search sorting May 28, 2026
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LeetCode 1171 - Remove Zero Sum Consecutive Nodes from Linked List

The problem requires us to repeatedly remove consecutive nodes in a singly-linked list whose values sum to zero. The input is the head of a singly-linked list, where each node has an integer value in the range -1000 to 1000, and the list length ranges from 1 to 1000 nodes.
leetcode Medium hash-table linked-list May 28, 2026
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LeetCode 1172 - Dinner Plate Stacks

The problem asks us to design a data structure that behaves like an infinite row of stacks, where every stack has the same fixed capacity. Instead of working with a single stack, we maintain many stacks indexed from left to right starting at 0.
leetcode Hard hash-table stack design heap-(priority-queue) May 28, 2026
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LeetCode 1173 - Immediate Food Delivery I

The problem is asking to calculate the percentage of immediate food deliveries from a delivery table. An immediate delivery is defined as one where the customerprefdeliverydate matches the orderdate.
leetcode Easy database May 28, 2026
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LeetCode 1174 - Immediate Food Delivery II

The problem provides a Delivery table that records food delivery orders. Each row represents a single order placed by a customer. Along with the order date, each customer also specifies a preferred delivery date.
leetcode Medium database May 28, 2026
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LeetCode 1175 - Prime Arrangements

The problem asks us to count how many permutations of numbers from 1 to n satisfy a specific condition: all prime numbers must appear at prime-numbered indices (1-indexed).
leetcode Easy math May 28, 2026
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LeetCode 1176 - Diet Plan Performance

The problem is asking us to simulate a dieter’s performance over a sequence of days based on their calorie consumption. The input is an array calories where calories[i] represents the number of calories consumed on day i. We are also given three integers: k, lower, and upper.
leetcode Easy array sliding-window May 28, 2026
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LeetCode 1177 - Can Make Palindrome from Substring

The problem asks us to determine whether certain substrings of a given string s can be rearranged and partially modified to form a palindrome. A palindrome is a string that reads the same forward and backward.
leetcode Medium array hash-table string bit-manipulation prefix-sum May 28, 2026
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LeetCode 1178 - Number of Valid Words for Each Puzzle

The problem asks us to determine, for each given puzzle string, how many words from a given list words are valid for that puzzle. A word is valid for a puzzle if it contains the first character of the puzzle and all characters of the word are also present in the puzzle.
leetcode Hard array hash-table string bit-manipulation trie May 28, 2026
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LeetCode 1179 - Reformat Department Table

The problem is asking us to take a table Department that records revenue per department per month in a vertical format and convert it into a horizontal format, often called a "pivot" table. In the input, each row contains a department id, a revenue value, and a month.
leetcode Easy database May 28, 2026
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LeetCode 1180 - Count Substrings with Only One Distinct Letter

The problem asks us to count how many substrings of a given string contain only one distinct character. A substring is a contiguous section of the string. For example, in the string "aaaba", the substring "aaa" is valid because every character is 'a'.
leetcode Easy math string May 28, 2026
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LeetCode 1181 - Before and After Puzzle

The problem gives us an array of phrases, where each phrase is a string made of lowercase English letters and spaces. Every phrase is well-formed, meaning there are no leading or trailing spaces and no consecutive spaces.
leetcode Medium array hash-table string sorting May 28, 2026
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LeetCode 1182 - Shortest Distance to Target Color

The problem gives us an array called colors, where each position contains one of three possible values: 1, 2, or 3. Each value represents a color assigned to that index. We are also given a list of queries.
leetcode Medium array binary-search dynamic-programming May 28, 2026
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LeetCode 1183 - Maximum Number of Ones

The problem gives us a binary matrix M with dimensions height x width. Every cell in the matrix must contain either 0 or 1. There is one important restriction: Every square submatrix of size sideLength x sideLength may contain at most maxOnes cells equal to 1.
leetcode Hard math greedy sorting heap-(priority-queue) May 28, 2026
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LeetCode 1184 - Distance Between Bus Stops

In this problem, we are given a circular bus route with n stops numbered from 0 to n - 1. The array distance describes the distance between neighboring stops. Specifically, distance[i] represents the distance from stop i to stop (i + 1) % n.
leetcode Easy array May 28, 2026
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LeetCode 1185 - Day of the Week

This problem asks us to determine which day of the week corresponds to a given calendar date. The input consists of three integers: - day, representing the day within the month - month, representing the month number from 1 to 12 - year, representing the year We must return the…
leetcode Easy math May 28, 2026
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LeetCode 1186 - Maximum Subarray Sum with One Deletion

The problem is asking us to find the maximum sum of a contiguous subarray in a given integer array, with the additional twist that we are allowed to delete at most one element from that subarray.
leetcode Medium array dynamic-programming May 28, 2026
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LeetCode 1187 - Make Array Strictly Increasing

The problem is asking us to transform the array arr1 into a strictly increasing array using the minimum number of operations. Each operation allows replacing an element of arr1 with an element from arr2.
leetcode Hard array binary-search dynamic-programming sorting May 28, 2026
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LeetCode 1188 - Design Bounded Blocking Queue

This problem asks us to implement a thread-safe bounded blocking queue, which is a data structure that stores elements in a first-in-first-out (FIFO) order, but with the added constraint that multiple threads may be concurrently accessing it.
leetcode Medium concurrency May 28, 2026
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LeetCode 1189 - Maximum Number of Balloons

The problem asks us to determine the maximum number of times the word "balloon" can be formed using the characters from a given string text. Each character in text can be used at most once per occurrence of the word.
leetcode Easy hash-table string counting May 28, 2026
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LeetCode 1190 - Reverse Substrings Between Each Pair of Parentheses

The problem gives us a string s containing lowercase English letters and balanced parentheses. Our task is to repeatedly reverse the substrings enclosed inside every matching pair of parentheses, starting from the innermost pair first.
leetcode Medium string stack May 28, 2026
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LeetCode 1191 - K-Concatenation Maximum Sum

This problem asks us to find the maximum possible sum of a contiguous subarray when we are allowed to delete at most one element from that chosen subarray. The important detail is that the resulting subarray must still contain at least one element after deletion.
leetcode Medium array dynamic-programming May 28, 2026
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LeetCode 1192 - Critical Connections in a Network

This problem gives us an undirected graph representing a network of servers. Each server is identified by an integer from 0 to n - 1, and each pair [a, b] in connections represents a bidirectional edge between server a and server b.
leetcode Hard depth-first-search graph-theory biconnected-component May 28, 2026
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LeetCode 1193 - Monthly Transactions I

The problem is asking us to produce aggregated statistics on transactions, grouped by month and country, from the Transactions table.
leetcode Medium database May 28, 2026
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LeetCode 1194 - Tournament Winners

The problem asks us to determine the winner in each group of players based on their accumulated points across multiple matches. We are given two tables: Players and Matches.
leetcode Hard database May 28, 2026
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LeetCode 1195 - Fizz Buzz Multithreaded

The problem asks us to coordinate four separate threads so they collectively print the correct Fizz Buzz sequence in order from 1 to n. Unlike the classic single threaded Fizz Buzz problem, this version introduces concurrency.
leetcode Medium concurrency May 28, 2026
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LeetCode 1196 - How Many Apples Can You Put into the Basket

This problem is asking us to determine how many apples we can fit into a basket with a maximum carrying capacity of 5000 units of weight. We are given an array weight where each element represents the weight of a single apple.
leetcode Easy array greedy sorting May 28, 2026
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LeetCode 1197 - Minimum Knight Moves

This problem asks us to compute the minimum number of moves a knight needs to travel from the origin [0, 0] to a target position [x, y] on an infinite chessboard.
leetcode Medium breadth-first-search May 28, 2026
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LeetCode 1198 - Find Smallest Common Element in All Rows

The problem asks us to find the smallest element that appears in every row of a given m x n matrix mat, where each row is sorted in strictly increasing order. In other words, we need an element that is common to all rows and is the minimum among all such elements.
leetcode Medium array hash-table binary-search matrix counting May 28, 2026
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LeetCode 1199 - Minimum Time to Build Blocks

The problem requires determining the minimum amount of time to build all blocks using workers that can either build blocks or split into more workers. You are given a list blocks where blocks[i] indicates the time it takes for a worker to complete the i-th block.
leetcode Hard array math greedy heap-(priority-queue) May 28, 2026