algorithm: Square free integer (#3760)

* feat: Add square free integer implementation

Closes #3402

* test: Add unit tests for square free integer

Closes #3402

* fix: Fix failing build

Changed static import for assertEquals()
Closes #3402

src/main/java/com/thealgorithms/maths/SquareFreeInteger.java

@@ -0,0 +1,42 @@
+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();
+	}
+}