Given a collection of distinct integers, return all possible permutations.
Example:
Input: [1,2,3] Output: [ [1,2,3], [1,3,2], [2,1,3], [2,3,1], [3,1,2], [3,2,1] ]
AC code:
class Solution {
public:
vector<vector<int>> permute(vector<int>& nums) {
vector<vector<int>> v;
iteration(nums, v, 0);
return v;
}
void iteration(vector<int>& nums, vector<vector<int>>& v, int begin) {
if (begin >= nums.size()) {
v.push_back(nums);
return;
}
for (int i = begin; i < nums.size(); ++i) {
swap(nums[begin], nums[i]);
iteration(nums, v, begin+1);
swap(nums[begin], nums[i]);
}
}
};
Runtime: 12 ms, faster than 42.11% of C++ online submissions for Permutations.
原文：https://www.cnblogs.com/ruruozhenhao/p/9803222.html