A

```
package com.thealgorithms.maths;
/*
* Java program for Square free integer
* This class has a function which checks
* if an integer has repeated prime factors
* and will return false if the number has repeated prime factors.
* true otherwise
* Wikipedia: https://en.wikipedia.org/wiki/Square-free_integer
*
* Author: Akshay Dubey (https://github.com/itsAkshayDubey)
*
* */
import java.util.HashSet;
import java.util.List;
public class SquareFreeInteger {
/**
* This method returns whether an integer is square free
*
* @param number Integer value which is to be checked
* @return false when number has repeated prime factors
* true when number has non repeated prime factors
* @throws IllegalArgumentException when number is negative or zero
*/
public static boolean isSquareFreeInteger(int number) {
if(number <= 0) {
//throw exception when number is less than or is zero
throw new IllegalArgumentException("Number must be greater than zero.");
}
//Store prime factors of number which is passed as argument
//in a list
List<Integer> primeFactorsList = PrimeFactorization.pfactors(number);
//Create set from list of prime factors of integer number
//if size of list and set is equal then the argument passed to this method is square free
//if size of list and set is not equal then the argument passed to this method is not square free
return primeFactorsList.size() == new HashSet<>(primeFactorsList).size();
}
}
```