LeetCode 46. 全排列

class Solution {
public:
    void PT(vector<vector<int>>& res, const vector<int>& nums, vector<bool>& num, vector<int>& paixu) {
        
        for (int j = 0; j < nums.size(); ++j) {
            if (num[j] == true) {
                num[j] = false;
                paixu.push_back(nums[j]);
                PT(res, nums, num, paixu);
                num[j] = true;
                if (paixu.size() == nums.size()) {
                    res.push_back(paixu);
                }
                paixu.pop_back();
            }
        }
        
    }
    vector<vector<int>> permute(vector<int>& nums) {
        vector<vector<int>> res;
        vector<bool> num(nums.size(), true);
        vector<int> paixu;
    
        PT(res, nums, num, paixu);
        return res;
    }
};