Kotlin - Completed Prime Factor Calculator

Rust - Refactored Hello World

kotlin/prime-factors/src/main/kotlin/PrimeFactorCalculator.kt

@@ -0,0 +1,39 @@
+class PrimeFactorCalculator {
+    companion object {
+        fun primeFactors(num: Int): List<Int> = primeFactors(num.toLong()).map { it.toInt() }
+
+        fun primeFactors(num: Long): List<Long> {
+            var tempNum = num
+            val returnList = mutableListOf<Long>()
+            while (tempNum != 1L){
+                val smallestPrimeFactor = tempNum.smallestPrimeFactor()
+                returnList.add(smallestPrimeFactor)
+                tempNum /= smallestPrimeFactor
+                if (smallestPrimeFactor == 1L){
+                    tempNum = 1L
+                }
+            }
+            return returnList
+        }
+    }
+}
+
+fun Int.isPrime(): Boolean = this.toLong().isPrime()
+
+fun Long.isPrime(): Boolean {
+    for (i in 2..Math.sqrt(this.toDouble()).toLong()) {
+        if (this.rem(i) == 0L) return false
+    }
+    return true
+}
+
+fun Int.smallestPrimeFactor(): Int = this.toLong().smallestPrimeFactor().toInt()
+
+fun Long.smallestPrimeFactor(): Long{
+    for (i in 2..this){
+        if (this.rem(i) == 0L){
+            return i
+        }
+    }
+    return 1
+}

rust/hello-world/src/lib.rs

@@ -1,8 +1,8 @@
 pub fn hello(name: Option<&str>) -> String {
-	let mut returnString: String;
+	let return_string: String;
 	match name {
-		Some(name) 	=> returnString = "Hello, ".to_string() + &name.to_string() + "!",
-		None		=> returnString = "Hello, World!".to_string(),
+		Some(name) 	=> return_string = "Hello, ".to_string() + &name.to_string() + "!",
+		None		=> return_string = "Hello, World!".to_string(),
 	}
-	return returnString;
-}
+	return return_string;
+}