CCF201409-2 画图(JAVA)

import java.util.Scanner;

public class Main{
    static int N = 105;
    static int a[][] = new int[N][N];
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = scanner.nextInt();
        while(n-->0) {
            int x1 = scanner.nextInt();
            int y1 = scanner.nextInt();
            int x2 = scanner.nextInt();
            int y2 = scanner.nextInt();
            for(int i = x1; i < x2; i ++) {
                for(int j = y1; j < y2; j++) {
                    a[i][j] = 1;
                }
            }
        }
        int res = 0;
        for(int i = 0 ; i < 100; i ++) {
            for(int j = 0 ; j < 100; j ++) {
                if(a[i][j]==1) res++;
            }
        }
        System.out.println(res);
    }   
}