poj 2739 Sum of Consecutive Prime Numbers

#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<algorithm>
#include<cmath>
#include<cstring>
using namespace std;
int prime[2024],cnt,sum;
void Prime(  )
{
bool hash[5024] = { 0 };
int t = ( int )sqrt( 10000.0 ) + 1;
for( int i = 3 ; i <= t; i +=2 )
{
if( !hash[i>>1] )
{
int tt = i << 1;
for( int j = i*i ; j <= 10000 ; j += tt )
hash[j>>1] = true;
}
}
cnt = 0;
prime[cnt++] = 2;
t = 10000/2;
for( int i = 1 ; i <= t ; i ++ )
{
if( !hash[i] )
{
prime[cnt++] = ( i<<1 ) + 1;
}
}
}
int Research( int num )
{
int i = cnt -1;
int ans = 0;
while( prime[i] > num )
i--;
for( ; i >= 0; i -- )
{
int sum = prime[i];
int j = i -1;
while( sum < num && j >=0 )
{
sum += prime[j];
j --;
}
if( sum == num ) ans++;
}
return ans;
}
int main( )
{
Prime();
int n;
while( scanf( "%d",&n ) ,n )
{
printf( "%d\n",Research( n  ) );
}
return 0;
}