Euler’s criterion in java

According to Euler’s criterion a square root of n under modulo p exists if and only if a number num exists such that num%p is equal to n%p.

Program

import java.util.Scanner; public class EulersCriterion {    public static void main(String args[]) {       Scanner sc = new Scanner(System.in);       System.out.println("Enter n value :");             int n = sc.nextInt();       System.out.println("Enter p value :");       int p = sc.nextInt();       n = n % p;       int flag = 0;            for (int num = 2; num < p; num++) {          if ((num * num) % p == n) {             flag = 1;          }       }       if(flag==1) {          System.out.println("root of a number under modulo p exists ");       } else {           System.out.println("root of a number under modulo p does not exists ");       }    } }

Output

Enter n value : 2 Enter p value : 7 root of a number under modulo p exists