add kotlin solution for 231 Power-Of-Two.kt

Author: MagicienDeCode

June-LeetCoding-Challenge/08-Power-Of-Two/Power-Of-Two.kt

@@ -0,0 +1,61 @@
+class PowerofTwoKotlin231 {
+
+    companion object {
+        val resultSet = setOf(
+            1,
+            2,
+            4,
+            8,
+            16,
+            32,
+            64,
+            128,
+            256,
+            512,
+            1024,
+            2048,
+            4096,
+            8192,
+            16384,
+            32768,
+            65536,
+            131072,
+            262144,
+            524288,
+            1048576,
+            2097152,
+            4194304,
+            8388608,
+            16777216,
+            33554432,
+            67108864,
+            134217728,
+            268435456,
+            536870912,
+            1073741824
+        )
+    }
+
+    fun isPowerOfTwo(n: Int): Boolean {
+        return resultSet.contains(n)
+    }
+    /*
+   fun isPowerOfTwo(n: Int): Boolean {
+       if (n == 1) {
+           return true
+       }
+       var current = 2
+       while (current < n && current <= 1073741823) {
+           current = current.shl(1)
+       }
+       return current == n
+   }
+    */
+}
+
+fun main() {
+    val solution = PowerofTwoKotlin231()
+    println(solution.isPowerOfTwo(4))
+    println(solution.isPowerOfTwo(1073741825))
+    println(solution.isPowerOfTwo(2))
+}