@@ -0,0 +1,26 @@
+package add_binary;
+
+public class AddBinary {
+
+    public class Solution {
+        public String addBinary(String a, String b) {
+            StringBuilder re = new StringBuilder();
+            int i = a.length() - 1;
+            int j = b.length() - 1;
+            int carry = 0;
+            while (i >= 0 || j >= 0 || carry > 0) {
+                int valueA = i < 0 ? 0 : a.charAt(i) - '0';
+                int valueB = j < 0 ? 0 : b.charAt(j) - '0';
+                re.append((valueA + valueB + carry) % 2);
+                carry = (valueA + valueB + carry) / 2;
+                i--;
+                j--;
+            }
+            return re.reverse().toString();
+        }
+    }
+
+    public static class UnitTest {
+
+    }
+}