Codeforces Round #629 (Div. 3) 1328B - K-th Beautiful String Solution

 

Problem  Link :  https://codeforces.com/problemset/problem/1328/B

Solution in C++:

///La ilaha illellahu muhammadur rasulullah

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

///Abul Hasnat  Tonmoy

///Department of CSE,23rd batch

///Islamic University,Bangladesh

///**********ALLAH IS ALMIGHTY************///

#include <bits/stdc++.h>

using namespace std;

using ll = long long ;

int main()

{

    ios_base::sync_with_stdio(0);

    cin.tie(0);

    int  t;

    cin >> t;

    while ( t-- )

    {

        int n,k,i;

        cin>>n>>k;

        ll s=0, pos=0;

        for(i = 0 ; ; i++ )

        {

            s+=i;

            if(s>=k)

            {

                pos=i;

                break;

            }

        }

        int  u,v;

        u=n-pos-1;

        v=n-(k-(pos*(pos-1)/2));

        for(i = 0 ; i < n ; i++)

        {

            if(i==u||i==v)

                cout<<"b";

            else

                cout<<"a";

        }

        cout<<endl;

    }

}