poj1195 Mobile phones 二维树状数组

   做得有点苦逼，各种错误，但最后还是被我发现了

#include <iostream>
#include<cstdio>
#include<cstring>

using namespace std;
int c[1025][1025],n;

inline int lowbit(int k)
{
    return k&(-k);
}

void insert(int x,int y,int d)
{
    for(int i=x;i<=n;i+=lowbit(i))
        for(int j=y;j<=n;j+=lowbit(j))
            c[i][j]+=d;
}

int getsum(int x,int y)
{
    int t=0;
    for(int i=x;i>0;i-=lowbit(i))
        for(int j=y;j>0;j-=lowbit(j))
            t+=c[i][j];
    return t;
}

int main()
{
    int x1,y1,x2,y2,d,x;
    while(~scanf("%d",&x))
    {
        if(x==3)
            break;
        if(x==0)
        {
            scanf("%d",&n);
            //memset(c,0,sizeof(int)*(n+1)*(n+1));对于二维数组不能这样初始化
            for(int i=0;i<=n;i++)
                for(int j=0;j<=n;j++)
                    c[i][j]=0;
        }
        else if(x==1)
        {
            scanf("%d%d%d",&x1,&y1,&d);
            x1++;y1++;
            insert(x1,y1,d);
        }
        else
        {
            scanf("%d%d%d%d",&x1,&y1,&x2,&y2);
            x1++;y1++;x2++;y2++;
            int sum=getsum(x2,y2)-getsum(x1-1,y2)-getsum(x2,y1-1)+getsum(x1-1,y1-1);
            printf("%d\n",sum);
        }
    }
    return 0;
}
/*
0 4
1 1 2 3
2 0 0 2 2
1 1 1 2
1 1 2 -1
2 1 1 2 3
3
*/