9063번 대지

import java.util.*;
class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        
        int max_x = Integer.MIN_VALUE;
        int min_x = Integer.MAX_VALUE;
        int max_y = Integer.MIN_VALUE;
        int min_y = Integer.MAX_VALUE;
        
        for(int i = 0 ; i < n ; i ++){
            int x = sc.nextInt();
            int y = sc.nextInt();
            max_x = Math.max(max_x,x);
            min_x = Math.min(min_x,x);
            max_y = Math.max(max_y,y);
            min_y = Math.min(min_y,y);
        }
        
        int value_x = max_x - min_x;
        int value_y = max_y - min_y;
        int result = value_x * value_y;
        System.out.print(result);
    }
}

배열로도 해결 가능