67. Add Binary (java)

Author: bluesword12350

solution/0067.Add Binary/Solution.java

@@ -0,0 +1,20 @@
+class Solution {
+    public String addBinary(String a, String b) {
+        int al = a.length(), bl = b.length(), di = Math.max(al, bl);
+        char[] ac = a.toCharArray(), bc = b.toCharArray(), re = new char[di + 1];
+        boolean jw = false;
+        for (int i = 1; i <= di; i++) {
+            int alc = al - i , blc = bl - i;
+            char aChar = alc >= 0 ? ac[alc] : '0';
+            char bChar = blc >= 0 ? bc[blc] : '0';
+            if (aChar == bChar) {
+                re[di + 1 - i] = jw ? '1' : '0';
+                jw = aChar == '1';
+            } else re[di + 1 - i] = jw ? '0' : '1';
+        }
+        if (jw) re[0] = '1';
+        StringBuilder builder = new StringBuilder();
+        for (char c : re) if (c != 0) builder.append(c);
+        return builder.toString();
+    }
+}