The Great Kian | Competitive Programming Questions with Answers in Java

Competitive Programming Questions with Answers in Java

The Great Kian

Problem

The great Kian is looking for a smart prime minister. He's looking for a guy who can solve the OLP (Old Legendary Problem). OLP is an old problem (obviously) that no one was able to solve it yet (like P=NP).

But still, you want to be the prime minister really bad. So here's the problem:

Given the sequence a1, a2, ..., an find the three values a1 + a4 + a7 + ..., a2 + a5 + a8 + ... and a3 + a6 + a9 + ... (these summations go on while the indexes are valid).

Input
The first line of input contains a single integer n (1 ≤ n ≤ 105).
The second line contains n integers a1, a2, ..., an separated by space (1 ≤ ai ≤ 109).

Output
Print three values in one line (the answers).

Sample Input
5

1 2 3 4 5

Sample Output
5 7 3

Solution

import java.util.*;

class TestClass {

    public static void main(String args[] ) throws Exception {

        int n, i;

        long n1=0, n2=0, n3=0;

        Scanner s = new Scanner(System.in);

        n = s.nextInt();

        int[] a = new int[n];

        for(i=0; i<n; i++)

        {

            a[i] = s.nextInt();

        }

        for(i=0; i<n; i = i + 3)

        {

            n1 = n1 + a[i];

            if(i+1 < n)

                n2 = n2 + a[i + 1];

            if(i+2 < n)

                n3 = n3 + a[i + 2];

        }

        System.out.println(n1 + " " + n2 + " " + n3);

    }

}