commit

Author: bryanfks-dev

67. Add Binary.java

@@ -0,0 +1,26 @@
+class Solution {
+    public String addBinary(String a, String b) {
+        int carry = 0;
+        int ai = a.length() - 1;
+        int bi = b.length() - 1;
+
+        // sb is a variable to save the result
+        StringBuilder sb = new StringBuilder();
+
+        while (ai >= 0 || bi >= 0 || carry == 1) {
+            if (ai >= 0)
+                carry += a.charAt(ai--) - '0';
+            
+            if (bi >= 0)
+                carry += b.charAt(bi--) - '0';
+
+            // Why mod 2 or div by 2, because this is in binary world
+            // or base 2 number, not a decimal number or base 10 number
+            sb.append(carry % 2);
+
+            carry /= 2;
+        }
+
+        return sb.reverse().toString();
+    }
+}