HDU 2138：How many prime numbers 【水】

How many prime numbers

Time Limit: 3000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 14709    Accepted Submission(s): 5106

Problem Description

  Give you a lot of positive integers, just to find out how many prime numbers there are.

 

Input

  There are a lot of cases. In each case, there is an integer N representing the number of integers to find. Each integer won’t exceed 32-bit signed integer, and each of them won’t be less than 2.

 

Output

  For each case, print the number of prime numbers you have found out.

 

Sample Input

32 3 4

 

Sample Output

2

 

AC-code:

#include<cstdio>#include<cmath>int main(){int n,ans,a,i,flag;while(scanf("%d",&n)!=EOF){ans=0;while(n--){flag=0;scanf("%d",&a);int k=sqrt(a);for(i=2;i<=k;i++)if(a%i==0){flag=1;break;}if(!flag)ans++;}printf("%d\n",ans);}return 0; }