Lecture39.cpp

#include<iostream>
#include<vector>
using namespace std;

class Solution {
private:
    void solve(vector<int> nums, int index, vector<vector<int> >& ans) {
        //base case
        if(index >= nums.size()) {
            ans.push_back(nums);
            return ;
        }
        
        for(int i=0; i<nums.size(); i++) {

            swap(nums[index],nums[i]);
            
            // Recursion
            solve(nums, index+1, ans);

            // back tracking 
            swap(nums[index],nums[i]);    
        }
        
    }
    
public:
    vector<vector<int>> permute(vector<int>& nums) {
        
        vector<vector<int> > ans;
        int index = 0;
        solve(nums, index, ans);
        return ans;
        
    }
};

int main(){
   
   return 0;
}