Codeforces--230B--T-primes_codeforces 230b

题目描述：
We know that prime numbers are positive integers that have exactly two distinct positive divisors. Similarly, we’ll call a positive integer t Т-prime, if t has exactly three distinct positive divisors.

You are given an array of n positive integers. For each of them determine whether it is Т-prime or not.
输入描述:
The first line contains a single positive integer, n (1 ≤ n ≤ 105), showing how many numbers are in the array. The next line contains n space-separated integers xi (1 ≤ xi ≤ 1012).

Please, do not use the %lld specifier to read or write 64-bit integers in С++. It is advised to use the cin, cout streams or the %I64d specifier.
输出描述:
Print n lines: the i-th line should contain “YES” (without the quotes), if number xi is Т-prime, and “NO” (without the quotes), if it isn’t.
输入：
3
4 5 6
输出：
YES
NO
NO
题意：
判断一个数是不是只有三个因子
题解：
只有三个因子的数，肯定是素数，且是个完全平方数，欧拉筛筛素数，判断就完事了。
代码：

#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
1
2
3
4