HDU 1556 Color the ball

HDU 1556 Color the ball

树状数组的简单题。
以下是我的代码：

#include < cstdio >
#include < cstring >
#define  lowbit(x) ((x)&(-(x)))
using   namespace  std;
const   int  kMaxn( 100007 );

int  n,bit[kMaxn];

void  Add( int  x, int  delta)
{
     for ( int  i = x;i <= n;i += lowbit(i))
        bit[i] += delta;
}

int  Value( int  x)
{
     int  re( 0 );
     for ( int  i = x;i > 0 ;i -= lowbit(i))
        re += bit[i];
     return  re;
}

int  main()
{
     // freopen("data.in","r",stdin);
    
     while (scanf( " %d " , & n) == 1   &&  n)
    {
        memset(bit, 0 , sizeof (bit));
         for ( int  i = 1 ;i <= n;i ++ )
        {
             int  a,b;
            scanf( " %d%d " , & a, & b);
            Add(a, 1 );
            Add(b + 1 , - 1 );
        }
        
         for ( int  i = 1 ;i <= n;i ++ )
        {
             if (i != 1 )
                printf( "   " );
            printf( " %d " ,Value(i));
        }
        printf( " \n " );
    }
    
     return   0 ;
}