comefrom: <awangdev>67. Add Binary_1.java
code: public String addBinary(String a, String b) {
          StringBuilder sb = new StringBuilder();
          int i = a.length() - 1, j = b.length() -1, carry = 0;
          while (i >= 0 || j >= 0) {
              int sum = carry;
              if (i >= 0) sum += a.charAt(i--) - '0';
              if (j >= 0) sum += b.charAt(j--) - '0';
              sb.insert(0, sum % 2);
              carry = sum / 2;
          }
          if (carry != 0) sb.insert(0, carry);
          return sb.toString();
      }
masked: public String var_0 ( String var_2 , String var_3 ) {
    StringBuilder var_5 = new StringBuilder ( ) ;
    int var_8 = var_2 . length ( ) - 1 , var_9 = var_3 . length ( ) - 1 , var_11 = 0 ;
    while ( var_8 >= 0 || var_9 >= 0 ) {
      int var_12 = var_11 ;
      if ( var_8 >= 0 ) var_12 += var_2 . charAt ( var_8 -- ) - '0' ;
      if ( var_9 >= 0 ) var_12 += var_3 . charAt ( var_9 -- ) - '0' ;
      var_5 . insert ( 0 , var_12 % 2 ) ;
      var_11 = var_12 / 2 ;
    }
    if ( var_11 != 0 ) var_5 . insert ( 0 , var_11 ) ;
    return var_5 . toString ( ) ;
  }
  