LeetCode46. 全排列

 1 class Solution {
 2 public:
 3     vector<int>path;
 4     vector<vector<int>>res;
 5     void backtracking(vector<int>nums,vector<bool>used){
 6         if(path.size() == nums.size()){
 7             res.push_back(path);
 8             return;
 9         }
10         for(int i = 0;i < nums.size();i++){
11             if(used[i]) continue;
12             used[i] = true;
13             path.push_back(nums[i]);
14             backtracking(nums,used);
15             path.pop_back();
16             used[i] = false;
17         }
18     }
19     vector<vector<int>> permute(vector<int>& nums) {
20         vector<bool>used(nums.size(),false);
21         backtracking(nums,used);
22         return res;
23     }
24 };