hdu--2138

来源：互联网发布：php foreach循环编辑：程序博客网时间：2024/06/16 22:33

How many prime numbers

Time Limit: 3000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 14698 Accepted Submission(s): 5098

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
解题思路:并不是所有的求素数都打表的,打表是用来求一段区间的,这里是离散的数值,只要暴力判断就行了.
代码如下:
#include<stdio.h>#include<cmath>int main(){int t;int flag,sum,n;while(scanf("%d",&t)!=EOF){      sum=0;for(int i=1;i<=t;i++){flag=0;scanf("%d",&n);for(int j=2;j<=sqrt(n);j++){if(n%j==0){flag=1;break;}}if(!flag)sum++;}printf("%d\n",sum);}return 0;}

0 0