LeetCode--Next Permutation

 1 class Solution {
 2 public:
 3     void nextPermutation(vector<int> &num) {
 4         int end = num.size() - 1;
 5         int povit = end;
 6         while(povit > 0){
 7             if(num[povit] > num[povit - 1]) break;
 8             povit --;
 9         }
10         if(povit > 0){
11             povit --; 
12             int large = end;
13             while(num[large] <= num[povit]) large --;
14             swap(num[large] , num[povit]);
15             reverse(num.begin() + povit + 1 , num.end());
16         }else{
17             reverse(num.begin() , num.end());
18         }
19     }
20 };