Update _693.java (#42)

* Update _693.java

* Update _693.java

Author: Jian GU

src/main/java/com/fishercoder/solutions/_693.java

@@ -31,13 +31,20 @@
  */
 
 public class _693 {
-    public boolean hasAlternatingBits(int n) {
-        String binaryStr = Integer.toBinaryString(n);
-        for (int i = 1; i < binaryStr.length(); i++) {
-            if (binaryStr.charAt(i - 1) == binaryStr.charAt(i)) {
-                return false;
+    public static class Solution1 {
+        public boolean hasAlternatingBits(int n) {
+            String binaryStr = Integer.toBinaryString(n);
+            for (int i = 1; i < binaryStr.length(); i++) {
+                if (binaryStr.charAt(i - 1) == binaryStr.charAt(i)) {
+                    return false;
+                }
             }
+            return true;
+        }
+    }
+    public static class Solution2 {
+        public boolean hasAlternatingBits_oneline(int n) {
+            return Integer.bitCount(((n >> 1) ^ n) + 1) == 1;
         }
-        return true;
     }
 }