leetcode 31: Next Permutation

class Solution {public:    void nextPermutation(vector<int>& nums) {        for(int i=nums.size()-2;i>=0;i--)        {            if(nums[i]<nums[i+1])//find the place that the first ascending happens            {                int j;                for(j=nums.size()-1;j>i;j--)//find the number to be swapped with nums[i]                    if(nums[j]>nums[i])                        break;                swap(nums[i],nums[j]);                reverse(nums.begin()+i+1,nums.end());//make the descending sequence after i becomes ascending                return;            }        }        reverse(nums.begin(),nums.end());    }};