Codeforces Round #658 (Div. 1) 1381A1 - Prefix Flip (Easy Version) Solution

                                          

Problem Link :  https://codeforces.com/contest/1381/problem/A1 

 Solution in C++:

///La ilaha illellahu muhammadur rasulullah

///******Bismillahir-Rahmanir-Rahim******///

///Abul Hasnat  Tonmoy

///Department of CSE,23rd batch

///Islamic University,Bangladesh

#include <bits/stdc++.h>

using namespace std;

int main()

{

    long long  t,n,i;

    cin>>t;

    while(t--)

    {

        cin>>n;

        string a,b;

        vector<int>v;

        cin>>a>>b;

        if(a[0]!=b[0])

            v.push_back(1);

        for(i=1; i<n; i++)

        {

            if(a[i]!=b[i])

            {

                v.push_back(i+1);

                v.push_back(1);

                v.push_back(i+1);

            }

        }

        cout<<v.size()<<" ";

        for(i=0;i<v.size();i++)

        {

            cout<<v[i]<<" ";

        }

        cout<<endl;

    }

}