Create 067. Add Binary.java

Author: futurus

067. Add Binary.java

@@ -0,0 +1,35 @@
+public class Solution {
+    public String addBinary(String a, String b) {
+        StringBuilder sb = new StringBuilder();
+        int i = a.length(), j = b.length();
+        boolean carry = false;
+        
+        while (i > 0 || j > 0 || carry) {
+            char f = --i < 0 ? '0' : a.charAt(i);
+            char s = --j < 0 ? '0' : b.charAt(j);
+
+            if (f == '1' && s == '1') {
+                if (carry == true) {
+                    sb.insert(0, '1');
+                } else {
+                    sb.insert(0, '0');
+                    carry = true;
+                }
+            } else if (f == '0' && s == '0') {
+                if (carry == true) {
+                    sb.insert(0, '1');
+                    carry = false;
+                } else {
+                    sb.insert(0, '0');
+                }
+            } else {
+                if (carry == true) {
+                    sb.insert(0, '0');
+                } else {
+                    sb.insert(0, '1');
+                }
+            }
+        }
+        return sb.toString();
+    }
+}