题解 | 【模板】二维前缀和

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        int n = in.nextInt();
        int m = in.nextInt();
        int q = in.nextInt();

        long[][] prefix = new long[n+1][m+1];
        for (int i=1; i<=n; i++) {
            for (int j=1; j<=m; j++) {
                prefix[i][j] = prefix[i][j-1] + prefix[i-1][j] + in.nextInt() - prefix[i-1][j-1];
            }
        }

        while (q-- > 0) {
            int x1 = in.nextInt();
            int y1 = in.nextInt();
            int x2 = in.nextInt();
            int y2 = in.nextInt();

            long res = prefix[x2][y2] - prefix[x2][y1-1] - prefix[x1-1][y2] + prefix[x1-1][y1-1];
            System.out.println(res); 
        }


        while (in.hasNextInt()) { // 注意 while 处理多个 case
            int a = in.nextInt();
            int b = in.nextInt();
            System.out.println(a + b);
        }
    }
}