class Solution {
private:
vector<vector<int>> res;
vector<int> path;
void backtracking(vector<int>& nums, vector<bool>& used) {
if (path.size() == nums.size()) {
res.push_back(path);
return;
}
for (int i = 0; i < nums.size(); i++) {
if (used[i] == true) continue;
used[i] = true;
path.push_back(nums[i]);
backtracking(nums, used);
path.pop_back();
used[i] = false;
}
}
public:
vector<vector<int>> permute(vector<int>& nums) {
vector<bool> used(nums.size(), false);
backtracking(nums, used);
return res;
}
};