NextPermutation.cpp

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