Create 476. Number Complement.java

Author: futurus

Diff for: 476. Number Complement.java

@@ -0,0 +1,23 @@
+// https://leetcode.com/problems/number-complement
+
+public class Solution {
+    public int highestBit(int num) {
+        int pos = 0;
+        while (num != 0) {
+            pos++;
+            num >>= 1;
+        }
+        return pos;
+    }
+    
+    public int findComplement(int num) {
+        int highest = highestBit(num);
+        int ones = 0;
+        
+        for (int i = 1; i <= highest; i++) {
+            ones = (ones << 1) | 1;
+        }
+        
+        return ones ^ num;
+    }
+}