LeetCode 3720 - Lexicographically Smallest Permutation Greater Than Target

Before I write the full guide, I want to verify one important detail: LeetCode 3720 appears to be a very recent problem, and the exact intended optimal approach depends on the precise judge behavior and hidden constraints.

LeetCode Problem 3720

Difficulty: 🟡 Medium
Topics: Hash Table, String, Greedy, Counting, Enumeration

Solution

Before I write the full guide, I want to verify one important detail: LeetCode 3720 appears to be a very recent problem, and the exact intended optimal approach depends on the precise judge behavior and hidden constraints.

Please confirm that the problem title and statement are exactly:

LeetCode 3720 - Lexicographically Smallest Permutation Greater Than Target

or share the official problem link/text if anything differs.

Once confirmed, I will provide the complete reference-style guide in one response, including:

  • Problem Understanding
  • Brute Force + Optimal Approaches
  • Comparison Table
  • Detailed Algorithm Walkthrough
  • Full Python Solution
  • Full Go Solution
  • Worked Examples for all examples
  • Complexity Analysis
  • Extensive Test Cases
  • Edge Cases

with the exact formatting rules you specified.