Codeforces Beta Round #25 (Div. 2 Only) 25A - IQ test Solution

 

Problem Link :   https://codeforces.com/problemset/problem/25/A

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 n,i,a,f,j;

    vector<long long>od,ev,pri,nopri;

    cin>>n;

    for(i=1; i<=n; i++)

    {

        f=0;

        cin>>a;

        if(a%2==0)

            ev.push_back(i);

        else

            od.push_back(i);

        for(j=2; j*j<=a; j++)

        {

            if(a%j==0)

            {

                f=1;

                break;

            }

        }

        if(f==1)

            nopri.push_back(i);

            else

                pri.push_back(i);

    }

    if(ev.size()==1)

        cout<<ev[0]<<endl;

    else if(od.size()==1)

        cout<<od[0]<<endl;

    else if(nopri.size()==1)

        cout<<nopri[0]<<endl;

    else if(pri.size()==1)

        cout<<pri[0]<<endl;

}