1111: 우정수와 완전수

import java.util.Scanner;

public class Main

{

public static void main(String[] args)  {

    Scanner sc = new Scanner(System.in);

    int a = sc.nextInt();

    int b = sc.nextInt();

    for (int i=a;i<=b;i++) {

    int ys = sum_jys(i);

    if (ys==i) {

    System.out.println(ys); //완전수

    } else if (i==sum_jys(ys)) {

    System.out.println(i+" "+sum_jys(ys)); //우정수

    }

    }

    sc.close();

}

public static int sum_jys(int a) {

int sum=0;

for (int i=1;i<a;i++) {

if (a%i==0) sum+=i;

}

return sum;

}

}