power of two

fishercoder1534 · fishercoder1534 · commit c712926d5308 · 2016-08-07T17:53:19.000-07:00
diff --git a/EASY/src/easy/PowerOfTwo.java b/EASY/src/easy/PowerOfTwo.java
@@ -0,0 +1,20 @@
+package easy;
+/**231. Power of Two  QuestionEditorial Solution  My Submissions
+Total Accepted: 90169
+Total Submissions: 237048
+Difficulty: Easy
+Given an integer, write a function to determine if it is a power of two.*/
+public class PowerOfTwo {
+    public boolean isPowerOfTwo(int n) {
+        //after writing out the binary representation of some numbers: 1,2,4,8,16,32, you can easily figure out that
+        //every number that is power of two has only one bit that is 1
+        //then we can apply that cool trick that we learned from {@link easy.NumberOfIBits}: n&(n-1) which will clear the least significant bit in n to zero
+        if(n <= 0) return false;
+        return (n&(n-1)) == 0;
+    }
+    
+    public static void main(String...strings){
+        PowerOfTwo test = new PowerOfTwo();
+        System.out.println(test.isPowerOfTwo(14));
+    }
+}
