pku1195 Mobile phones

pku1195 Mobile phones

#include < iostream >
using   namespace  std;

int  N;
int  s[ 1100 ][ 1100 ];
int  lowbit( int  x){
     return  x ^ (x & (x - 1 ));
}
void  insert( int  x, int  y, int  val){
     for ( int  i = x;i <= N;i += lowbit(i))
         for ( int  j = y;j <= N;j += lowbit(j))
            s[i][j] += val;
}
int  updata( int  x, int  y)
{
     int  tmp = 0 ;
     for ( int  i = x;i;i -= lowbit(i))
         for ( int  j = y;j;j -= lowbit(j))
            tmp += s[i][j];
     return  tmp;
}
int  main()
{
     int  k;
     while ( 1 ){
        scanf( " %d " , & k);
         if (k == 0 ){
            scanf( " %d " , & N); N ++ ;
            memset(s, 0 , sizeof (s));
        }
         else   if (k == 1 ){
             int  x,y,val;
            scanf( " %d%d%d " , & x, & y, & val);
            insert(x + 1 ,y + 1 ,val);
        }
         else   if (k == 2 ){
             int  x1,y1,x2,y2;
            scanf( " %d%d%d%d " , & x1, & y1, & x2, & y2);
             int  ans = updata(x2 + 1 ,y2 + 1 ) - updata(x1,y2 + 1 ) -
                       updata(x2 + 1 ,y1) + updata(x1,y1);
            printf( " %d\n " ,ans);
        }
         else   break ;
    }
     return   0 ;
}