B. T-primes
binary search; implementation; math; number theory
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.
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.
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.
The given test has three numbers. The first number 4 has exactly three divisors — 1, 2 and 4, thus the answer for this number is ""YES"". The second number 5 has two divisors (1 and 5), and the third number 6 has four divisors (1, 2, 3, 6), hence the answer for them is ""NO"".