Permutations

class Solution {
public:

    void f(vector<int> nums, vector<vector<int>>&ans, vector<int>&cur, vector<int> &visited, int n){

        if(cur.size()==n){
            ans.push_back(cur);
            return;
        }

        for(int i=0; i<n; i++){

            if(visited[i]==0){
                visited[i] = 1;
                cur.push_back(nums[i]);
                f(nums,ans,cur,visited,n);
                cur.pop_back();
                visited[i] = 0;
            }

        }

    }

    vector<vector<int>> permute(vector<int>& nums) {
        vector<vector<int>> ans;
        vector<int> cur;
        int n = nums.size();
        vector<int> visited(n,0);

        f(nums,ans,cur,visited,n);

        return ans;

    }
};