http://acm.hdu.edu.cn/showproblem.php?pid=5104

 

#include
      
       #include
       
        #include
        
         #include
         
          #include
          
           using namespace std;int isp[10000+100];int prime[10000];int coun;bool isprime(int x){  int i,j;  for(i=2;i<=sqrt(x);i++)  {    if(x%i==0) return false;  }  return true;}void fun(){  int i,j;  for(i=2;i<=10000;i++)  {    if(isp[i]!=0) continue;    if(isprime(i))    {        isp[i]=1;        prime[coun++]=i;    }    j=i;    while(j+i<=10000)    {      j+=i;      isp[j]=2;    }  }}int main(){  //freopen("output.txt","w",stdout);  int ans;  int i,j,k,n;  memset(isp,0,sizeof(isp));  coun=0;  fun();  //printf("%d...\n",coun);  while(scanf("%d",&n)!=EOF)  {    int ans=0;    for(i=0;i
           
            n/3) break; for(j=i;prime[j]<=(n-prime[i])/2;j++) { k=n-prime[i]-prime[j]; if(isp[k]==1) ans++; } } printf("%d\n",ans); //n++; } return 0;}