矩阵的子矩阵——坐标范围内——求值

import java.util.Scanner;
class solution{
	int x1,x2,y1,y2;
	int sum=0;
	public void zuobiao(int[][] range,int k,int[][] grid){
		for(int q=0;q<k;q++) {
				int x1=range[q][0];
				int y1=range[q][1];
				int x2=range[q][2];
				int y2=range[q][3];
				for(int a=x1;a<x2+1;a++) {
					for(int b=y1;b<y2+1;b++) {
						sum=sum+grid[a][b];
					}
				}
				System.out.println(sum);
				sum=0;
			}	
		
	}
}
public class Overcome{
public static void main(String[] args) {
	int i,j,m,n,k,p,q;
	Scanner a=new Scanner(System.in);
	i=a.nextInt();
	j=a.nextInt();
	int[][] grid =new int[i][j];//存储输入矩阵
    for( m=0;m<i;m++) {
    	for( n=0;n<j;n++) {
    		grid[m][n]=a.nextInt();
    	}
    }
    k=a.nextInt();
    int[][] range=new int[k][4];//存储输入坐标
    for( p=0;p<k;p++) {
    	for( q=0;q<4;q++) {
    		range[p][q]=a.nextInt();
    	}
    }
    solution s=new solution();
    s.zuobiao(range,k,grid);
}
}