题解 | 【模板】二维前缀和

java

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);
        int n=in.nextInt();
        int m=in.nextInt();
        int q=in.nextInt();
        long[][] a=new long[n+1][m+1];
        for(int i=1;i<=n;i++){
            for(int j=1;j<=m;j++){
                a[i][j]=in.nextLong();
            }
        }
        long[][] presum=new long[n+1][m+1]; 
        for(int i=1;i<=n;i++){
            for(int j=1;j<=m;j++){
                presum[i][j]=presum[i-1][j]+presum[i][j-1]-presum[i-1][j-1]+a[i][j];
            }
        }
        while(q-->0){
            int x1=in.nextInt();
            int y1=in.nextInt();
            int x2=in.nextInt();
            int y2=in.nextInt();
            System.out.println(presum[x2][y2]-presum[x1-1][y2]-presum[x2][y1-1]+presum[x1-1][y1-1]);
        }



    }
}