poj 1195Mobile phones

http://poj.org/problem?id=1195

 #include <cstdio>
 #include <cstring>
 #include <algorithm>
 #define maxn 1026
 using namespace std;

 int a[maxn][maxn];
 int c[maxn][maxn];
 int S,x,y,aa,l,r,b,t,h,T;

 int lowbit(int x)
 {
     return x&(x^(x-));
 }

 void update(int i,int j,int k)
 {
     while(i<=S)
     {
         int temp=j;
         while(temp<=S)
         {
             c[i][temp]+=k;
             temp+=lowbit(temp);
         }
         i+=lowbit(i);
     }
 }

 int sum(int i,int j)
 {
     int sum1=;
     while(i>)
     {
         int temp=j;
         while(temp>)
         {
             sum1+=c[i][temp];
             temp-=lowbit(temp);
         }
         i-=lowbit(i);
     }
     return sum1;
 }

 int main()
 {
     while(scanf("%d",&h))
     {
         if(h==)
         {
             scanf("%d",&S);
             memset(c,,sizeof(c));
         }
         else if(h==) break;
         else if(h==)
         {
             scanf("%d%d%d",&x,&y,&aa);
             update(x+,y+,aa);
         }
         else if(h==)
         {
             scanf("%d%d%d%d",&l,&r,&b,&t);
             int sum1=sum(b+,t+);
             int sum2=sum(l,t+);
             int sum3=sum(b+,r);
             int sum4=sum(l,r);
             printf("%d\n",sum1-sum2-sum3+sum4);
         }
     }
     return ;
 }