Return-Path: william@bourbon.usc.edu
Delivery-Date: Sat Nov 22 08:16:32 2008
X-Spam-Checker-Version: SpamAssassin 3.2.3 (2007-08-08) on merlot.usc.edu
X-Spam-Level: 
X-Spam-Status: No, score=-2.4 required=5.0 tests=AWL,BAYES_00 autolearn=ham
	version=3.2.3
Received: from bourbon.usc.edu (bourbon.usc.edu [128.125.9.75])
	by merlot.usc.edu (8.14.1/8.14.1) with ESMTP id mAMGGW34002669
	for <cs551@merlot.usc.edu>; Sat, 22 Nov 2008 08:16:32 -0800
Received: from bourbon.usc.edu (localhost.localdomain [127.0.0.1])
	by bourbon.usc.edu (8.14.2/8.14.1) with ESMTP id mAMGENkS011538
	for <cs551@merlot>; Sat, 22 Nov 2008 08:14:23 -0800
Message-Id: <200811221614.mAMGENkS011538@bourbon.usc.edu>
To: cs551@merlot.usc.edu
Subject: Re: BitVector
Date: Sat, 22 Nov 2008 08:14:23 -0800
From: Bill Cheng <william@bourbon.usc.edu>

Someone wrote:

  > If thats the case I guess something is wrong with my code.
  > I was getting correct bitvector for all the cases except this
  > one. Just wanted to verify the rite answer. 
  > Sorry for any confusion and inconvinience.

Well, let's take the first word "desc" as an example.
echo -n "desc" | openssl md5 returns 1dee80c7d5ab2c1c90aa8d2f7dd47256.
The last 9 bits is 0x056.  0x056 equals 86.  Each character in the
bit-vector represents 4 bits.  So, 86 = 4*21 + 2.  So, if you count
from the right, you need to skip 21 characters.  Now, if the remainder
was zero, then the corresponding character in the bit-vector would be
have the "1" position set.  You have a "1" there.  Since the remainer
is 2, the corresponding character in the bit-vector should have the
"4" position set (1 shifted to the left by 2 bit positions).  I have
a "c" there.  So, the "4" bit is set.
--
Bill Cheng // bill.cheng@usc.edu <URL:http://merlot.usc.edu/william/usc/>





  ________________________________
  From: Bill Cheng <william@bourbon.usc.edu>
  To: cs551@merlot.usc.edu
  Sent: Friday, November 21, 2008 9:58:47 PM
  Subject: Re: BitVector
  
  Someone wrote:
  
    > For file v.gif with keywords : desc viterbi usc gif we get bitvector 
    > 
    > Bit-vector=00000000000000000000000000200000000000000000000000000000000000000000000000000000
    > 2008000000000000000000000000000000040000000000000000000000000000000000000000000000000000000
    > 0400008000000000000000000000000000000000000000000000000000000001000000000000000000000
    > 
    > 
    > while the grading guidelines says
    > 
    > Bit-vector= \
    >  0000000000000000000000002000000000000000000000 \
    >  0000000000000000000000000000002008000000000000 \
    >  0000000000000000040000000000000000000000000000 \
    >  0000000000000000000000000040000800000000000000 \
    >  0000000000000000000000000000000000000000c00000 \
    >  00000000000000
    > 
    > Kindly confirm which one is correct.
    > Ref: test case A 3
  
  If you think my solution is incorrect, please provide
  some evidence!
  --
  Bill Cheng // bill.cheng@usc.edu <URL:http://merlot.usc.edu/william/usc/>