refactor 89

Author: fishercoder1534

src/main/java/com/fishercoder/solutions/_89.java

@@ -1,22 +1,27 @@
 package com.fishercoder.solutions;
 
+import com.fishercoder.common.utils.CommonUtils;
+
 import java.util.ArrayList;
 import java.util.List;
 
 /**
  * 89. Gray Code
  *
  * The gray code is a binary numeral system where two successive values differ in only one bit.
-
- Given a non-negative integer n representing the total number of bits in the code, print the sequence of gray code. A gray code sequence must begin with 0.
+ * Given a non-negative integer n representing the total number of bits in the code,
+ * print the sequence of gray code.
+ * A gray code sequence must begin with 0.
 
  For example, given n = 2, return [0,1,3,2]. Its gray code sequence is:
 
  00 - 0
  01 - 1
  11 - 3
  10 - 2
+
  Note:
+
  For a given n, a gray code sequence is not uniquely defined.
 
  For example, [0,2,3,1] is also a valid gray code sequence according to the above definition.
@@ -34,4 +39,11 @@ public List<Integer> grayCode(int n) {
         return result;
     }
 
+    public static void main(String... args) {
+        int n = 3;
+        System.out.println("1 << n = " + (1 << n));
+        _89 test = new _89();
+        List<Integer> result = test.grayCode(n);
+        CommonUtils.printList(result);
+    }
 }