POJ 1195 Mobile phones【二维树状数组】

#include<iostream>
#define M 1300
int c[M][M],a[M][M],n;
int lowbit(int t){
return t&(t^(t-1));
}
int sum(int p,int q){
int x=p,y,total=0;
while(x>0){
y=q;
while(y>0){
total+=c[x][y];
y-=lowbit(y);
}
x-=lowbit(x);
}
return total;
}
void modify(int p,int q,int key){
int x=p,y;
while(x<=n){
y=q;
while(y<=n){
c[x][y]+=key;
y+=lowbit(y);
}
x+=lowbit(x);
}
}
int main()
{
int i,j,k,jj,kk,m,order,ans;
scanf("%d%d",&i,&n);
memset(c,0,sizeof(c));
memset(a,0,sizeof(a));
while(scanf("%d",&order)!=EOF){
if(order==3) break;
else if(order==1){
scanf("%d%d%d",&j,&k,&m);
++j;  ++k;
if(m<0&&m*(-1)>a[j][k]){
m=(-1)*a[j][k];
modify(j,k,m);
a[j][k]=0;
}
else{
modify(j,k,m);
a[j][k]+=m;
}
}
else if(order==2){
scanf("%d%d%d%d",&j,&jj,&k,&kk);
++j; ++jj; ++k; ++kk;
//printf("%d ",sum(n,n));
ans=sum(k,kk)+sum(j-1,jj-1)-sum(k,jj-1)-sum(j-1,kk);
printf("%d/n",ans);
}
}
}