poj 1195 mobile phone

题目连接：

题意:要求设计这样一个数据结构,支持下列操作

1.add(x,y,a).对二维数组的第x行,第y列加上a.

2.sum(l,b,r,t).求所有满足l<=x<=r,b<=y<=t,的数组元素的和

二位树状数组~

#include <iostream>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#define loop(s,i,n) for(i = s;i <= n;i++)
#define lowbit(x) x&-x
using namespace std;
int c[1050][1050];
int n;
void add(int a,int b,int val)
{
    int i,j;
    for(i = a;i <= n;i += lowbit(i))
    {
        for(j = b;j <= n;j += lowbit(j))
        c[i][j] += val;
    }
}

int sum(int a,int b)
{
    int res = 0;
    int i,j;
    for(i = a;i > 0;i -= lowbit(i))
    {
        for(j = b;j > 0;j -= lowbit(j))
        res+=c[i][j];
    }
    return res;
}
int main()
{
    int t,i,j,a,b,l,r;
    while(~scanf("%d",&t) != EOF)
    {
        if(!t)
        {
            scanf("%d",&n);
            loop(1,i,n)
            {
                loop(1,j,n)
                c[i][j] = 0;
            }
        }
        if(t == 1)
        {
            scanf("%d %d %d",&a,&b,&l);
            add(a+1,b+1,l);
        }
        else if(t == 2)
        {
            scanf("%d %d %d %d",&a,&b,&l,&r);
            printf("%d
",sum(a,b)+sum(l+1,r+1)-sum(a,r+1)-sum(l+1,b));
        }
        if(t == 3)
        break;
    }
    return 0;
}