POJ2739——DFS——Sum of Consecutive Prime Numbers

#include<cstdio>
#include<cstring>
#include<cmath>
using namespace std;
int pri[2000] = {2};
int count = 0;
void prime()
{
   int temp = 1;
   int i,j;
   for( i = 3; i <= 10000;i++){
        for( j = 2; j <= i/2;j++)
            if(i%j == 0)
            break;
       if(j > i/2) pri[temp++] = i;
   }
}
int num(int n,int i)
{
    if(n-pri[i] == 0)
        count++;
    else if( n - pri[i] > 0)
       num(n-pri[i],i-1);
    return 0;
}
int main()
{
    int n,k;
    prime();

    while(~scanf("%d",&n)&&n){
            count = 0;
    for(int i = 0; i < 2000;i++){
        if(pri[i] == n) {
            count++;
            k = i -1;
            break;
        }
        else if( n < pri[i]){
            k = i -1;
           break;
        }
    }
    for(int i = k ; i >= 0;i--)
      num(n,i);
    printf("%d\n",count);
    }
    return 0;
}