Find Product | Competitive Programming Questions with Answers in Java

Competitive Programming Questions with Answers in Java

Find Product

Problem

You have been given an array A of size N consisting of positive integers. You need to find and print the product of all the number in this array Modulo 109+7.

Input Format
The first line contains a single integer N denoting the size of the array. The next line contains N space separated integers denoting the elements of the array

Output Format
Print a single integer denoting the product of all the elements of the array Modulo 109+7.

Constraints
1≤N≤103
1≤A[i]≤103

Sample Input
5
1 2 3 4 5

Sample Output
120

Explanation

There are 5 integers to multiply. Let's store the final answer in answer variable. Since 1 is identity value for multiplication, initialize answeras 1.

So the process goes as follows:

answer=1
answer=(answer×1) % (109+7)
answer=(answer×2) % (109+7)
answer=(answer×3) % (109+7)
answer=(answer×4) % (109+7)
answer=(answer×5) % (109+7)

The above process will yield answer as 120

Solution

import java.util.*;

class TestClass {

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

        int n, i;

        long pro=1;

        Scanner s = new Scanner(System.in);

        n = s.nextInt();

        long a[] = new long[n];

        for(i=0; i<n; i++)

        {

          a[i] = s.nextInt();

          pro = (pro * (a[i]) % ((long) Math.pow(10,9) + 7));

        }

        System.out.println(pro);

    }

}