题意：给定矩阵，对点更新，询问给两个点，求这两个点构成矩形内元素和。
二维数组可以对点更新，sum 求的是（1，1）到（x，y）的和。
#include<iostream>
#include<cmath>
#include<queue>
#include<cstring>
#include<string>
#include<map>
#include<stack>
#include<set>
#include<cstdio>
#include<algorithm>
using namespace std;
int n;
int a[1050][1050];
int lowbit(int x){
return x&(-x);
}
void add2(int x,int y,int num){
for(int i = x; i <= n; i += lowbit(i))
for(int j = y; j <= n; j += lowbit(j))
a[i][j] += num;
}
int sum2(int x,int y){
int res = 0;
for(int i = x; i > 0; i -= lowbit(i))
for(int j = y; j > 0; j -= lowbit(j))
res += a[i][j];
return res;
}
int main(){
//freopen("a.txt", "r", stdin);
int x,y,w,xx,yy,q;
scanf("%d%d", &q, &n);
memset(a, 0, sizeof(a));
while(scanf("%d", &q) && q<3){
if(q==1){
scanf("%d%d%d", &x, &y, &w);
add2(++x, ++y, w);
}else if(q==2){
scanf("%d%d%d%d", &x, &y, &xx, &yy);
x++;y++;xx++;yy++;
printf("%dn", sum2(xx,yy)-sum2(x-1,yy)-sum2(xx,y-1)+sum2(x-1,y-1));
}
}
return 0;
}