check in source code

jianminchen · jianminchen · commit 76279a4ff2e7 · 2018-07-20T15:08:57.000-07:00
diff --git a/2017 July -/Leetcode 231 Power of two.cs b/2017 July -/Leetcode 231 Power of two.cs
@@ -0,0 +1,42 @@
+﻿using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Leetcode231_PowerOfTwo
+{
+    /// <summary>
+    /// Leetcode 231: Power of two 
+    /// https://leetcode.com/problems/power-of-two/description/
+    /// </summary>
+    class Program
+    {
+        static void Main(string[] args)
+        {
+        }
+
+        /// <summary>
+        /// 0 - false
+        /// 1 - true
+        /// 2 - true
+        /// 3 - false
+        /// 4 - true        
+        /// </summary>
+        /// <param name="n"></param>
+        /// <returns></returns>
+        public bool IsPowerOfTwo(int n)
+        {
+            if( n <= 0 )
+                return false;
+
+            if( n == 1 )
+                return true;
+
+            if (n % 2 == 1)
+                return false;
+
+            return IsPowerOfTwo(n / 2);
+        }
+    }
+}
diff --git a/Leetcode 231 Power of two.cs b/Leetcode 231 Power of two.cs
@@ -0,0 +1,42 @@
+﻿using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Leetcode231_PowerOfTwo
+{
+    /// <summary>
+    /// Leetcode 231: Power of two 
+    /// https://leetcode.com/problems/power-of-two/description/
+    /// </summary>
+    class Program
+    {
+        static void Main(string[] args)
+        {
+        }
+
+        /// <summary>
+        /// 0 - false
+        /// 1 - true
+        /// 2 - true
+        /// 3 - false
+        /// 4 - true        
+        /// </summary>
+        /// <param name="n"></param>
+        /// <returns></returns>
+        public bool IsPowerOfTwo(int n)
+        {
+            if( n <= 0 )
+                return false;
+
+            if( n == 1 )
+                return true;
+
+            if (n % 2 == 1)
+                return false;
+
+            return IsPowerOfTwo(n / 2);
+        }
+    }
+}
