update history

Author: jackzhenguo

UpdateHistory.md

@@ -118,3 +118,17 @@ https://github.com/jackzhenguo/LeetCodeManager
             return dist;
         }
    ```C#
+  ## Bit Mainpulation
+   *  [CSDN:#476 Number Complement](http://blog.csdn.net/daigualu/article/details/72843822)
+   > get bits for a number</br>
+   ```C#
+        public int FindComplement(int num)
+        {
+            int bits = 1; //num including bits
+            while (Math.Pow(2, bits) <= num)
+                bits++;
+            int sum = (int) Math.Pow(2, bits) - 1;//sum =Pow(2,n)-1: sum of n bits 1
+            return  sum - num; //sum - num is the complement
+
+        }
+   ```