HDU 1406 完数

水题

#include<stdio.h>
int p[10001];
void chart( )
{
     p[0] = 0;
     for( int i = 1; i <= 10010; ++i )
     {
          int f = 1,sum = 0;
          for( int k = 1; k <= i / 2; ++k )
          {
               if( i % k == 0 )
                   sum += k;
               if( sum > i )
                   break;
           }
           if( i == sum )
               p[i] = p[i - 1] + 1;
           else
               p[i] = p[i - 1];
      }
 }
int main( )
{
    chart( );
    int a,b,t;
    scanf( "%d",&t );
    while( t-- )
    {
           scanf( "%d%d",&b,&a );
           if( a < b )
               a ^= b ^= a ^= b;
           printf( "%d\n",p[a] - p[b-1] );
           }
    return 0;
}