LeetCode 数字排列问题 46 Permutations

题目链接

https://leetcode.com/problems/permutations/#/description

Given a collection of distinct numbers, return all possible permutations.

For example,
[1,2,3] have the following permutations:

[  [1,2,3],  [1,3,2],  [2,1,3],  [2,3,1],  [3,1,2],  [3,2,1]]

vector<vector<int>>permute(vector<int> nums){vector<vector<int>> permutions;if(nums.empty()) return permutions;perm(nums,0,permutions);return permutions;}void perm(vector<int>nums,int start,vector<vector<int>>&permutions){if(start == nums.size()){permutions.push_back(nums);return; }for(int i = start;i < nums.size();i++){swap(nums[start],nums[i]);perm(nums,start + 1,permutions);}}