LeetCode 46 全排列

class Solution {
public:
    vector<vector<int>> res;
    vector<int> path;
    bool used[10];

    void dfs(vector<int>& nums) {
        if (path.size() == nums.size()) {
            res.push_back(path);
            return;
        }

        for (int i = 0; i < nums.size(); i ++) {
            if (!used[i]) {
                used[i] = true;
                path.push_back(nums[i]);
                dfs(nums);
                path.pop_back();
                used[i] = false;
            }
            
        }
    }

    vector<vector<int>> permute(vector<int>& nums) {
        dfs(nums);

        return res;
    }
};