leetcode/src/s0031_next_permutation.cpp

#include "s0031_next_permutation.hpp"

void S0031::nextPermutation(vector<int>& nums) {
  int i = nums.size() - 2;
  while (i >= 0 && nums[i] >= nums[i + 1]) {
    i--;
  }
  if (i >= 0) {
    int j = nums.size() - 1;
    while (j >= 0 && nums[i] >= nums[j]) {
      j--;
    }
    swap(nums[i], nums[j]);
  }
  reverse(nums.begin() + i + 1, nums.end());
}