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_1 , String var_2 ) {
    StringBuilder var_3 = new StringBuilder ( ) ;
    int var_4 = var_1 . length ( ) - 1 , var_5 = var_2 . length ( ) - 1 , var_6 = 0 ;
    while ( var_4 >= 0 || var_5 >= 0 ) {
      int var_7 = var_6 ;
      if ( var_4 >= 0 ) var_7 += var_1 . charAt ( var_4 -- ) - '0' ;
      if ( var_5 >= 0 ) var_7 += var_2 . charAt ( var_5 -- ) - '0' ;
      var_3 . insert ( 0 , var_7 % 2 ) ;
      var_6 = var_7 / 2 ;
    }
    if ( var_6 != 0 ) var_3 . insert ( 0 , var_6 ) ;
    return var_3 . toString ( ) ;
  }
  