nextPermutation.cpp

class Solution {
public:
    void nextPermutation(vector<int>& nums) {
        int n = nums.size();
        int ind = -1;
        for(int i = n-2; i>=0; i--) {
            if(nums[i] < nums[i+1]) {
                ind = i;
                break;
            }
        }
        if (ind == -1) {
            reverse(nums.begin(), nums.end());
        } else {
            for (int i = n-1; i > ind; i--) {
                if (nums[i] > nums[ind]) {
                    swap(nums[i], nums[ind]);
                    break;
                }
            }
            int left = ind + 1;
            int right = n - 1;
            while (left < right) {
                swap(nums[left], nums[right]);
                left++;
                right--;
            }
        }
         
    }
};