poj 3978 Primes

#include<iostream>using namespace std;#define SIZE 10000 #define MAX_SIZE 100000 int a[SIZE];int counts = 0;void getPrimetable(){     counts = 0;     for(int i=2;i<MAX_SIZE;i++){        int flag = 0;        for(int j=0;j<counts;j++){if(i%a[j] == 0){       flag = 1;       break;}        }        if(flag == 0){ a[counts] = i; counts++;        }     }}int main(){    getPrimetable();    int n,m;    int ans = 0;    while(cin>>n>>m){      if(n== -1 && m== -1)        return 0;      ans = 0;      for(int i=0;i<counts;i++){   if(a[i]>=n &&a[i]<=m){      ans++;   }   if(a[i] >m){      break;   }      }      cout<<ans<<endl;    }    return 0;}