Day 13 : Print Permutations - String

#include <bits/stdc++.h> 

void helper(string &s, vector<int>&vis, string &ds, vector<string>&ans)
{
    if(ds.size()==s.size())
    {
        ans.push_back(ds);
        return;
    }
    for(int j=0;j<s.size();j++)
    {
        if(!vis[j])
        {
            ds+=s[j];
            vis[j]=1;
            helper(s,vis,ds,ans);
            vis[j]=0;
            ds.pop_back();
        }
    }
}

vector<string> findPermutations(string &s) {
    vector<string>ans;
    vector<int>vis(s.size(),0);
    string ds="";
    helper(s,vis,ds,ans);
    return ans;
}