# 1952. Three Divisors

## Description

Given an integer n, return true if n has exactly three positive divisors. Otherwise, return false.

An integer m is a divisor of n if there exists an integer k such that n = k * m.

Example 1:

Input: n = 2
Output: false
Explantion: 2 has only two divisors: 1 and 2.


Example 2:

Input: n = 4
Output: true
Explantion: 4 has three divisors: 1, 2, and 4.


Constraints:

• 1 <= n <= 104

## Solutions

• class Solution {
public boolean isThree(int n) {
int cnt = 0;
for (int i = 2; i < n; i++) {
if (n % i == 0) {
++cnt;
}
}
return cnt == 1;
}
}

• class Solution {
public:
bool isThree(int n) {
int cnt = 0;
for (int i = 2; i < n; ++i) {
cnt += n % i == 0;
}
return cnt == 1;
}
};

• class Solution:
def isThree(self, n: int) -> bool:
return sum(n % i == 0 for i in range(2, n)) == 1


• func isThree(n int) bool {
cnt := 0
for i := 2; i < n; i++ {
if n%i == 0 {
cnt++
}
}
return cnt == 1
}

• /**
* @param {number} n
* @return {boolean}
*/
var isThree = function (n) {
let cnt = 0;
for (let i = 2; i < n; ++i) {
if (n % i == 0) {
++cnt;
}
}
return cnt == 1;
};