Question

I am stuck on problem set 8 , question 4.

I've tried studying the maxVal function from lecture 13, i've thrown print statments all over it, but i cant figuew out exactly how and why it works. It doesn't return all the values that my pen and paper decision tree returns.

I am at the stage where i can use the slightly modified maxVal function to get me the highest Value for hours of study, but becasue I don't understand how it works completely, I can't begin to try and make it so that it also returns the subjects that provide that max value.

Help?

Answer 1

Hoot! You just asked your first question! Hang tight while I find people to answer it for you. You can thank people who give you good answers by clicking the 'Good Answer' button on the right!

Answer 2

paste your code at dpaste.com then post the link here. I spent a very long time on that one and almost understand how it works. - I'm pretty sure my implementation works.

Answer 3

Sorry for the delay, but I have completed the problem set now.

I used a method that I shamelessly copied from a blog by some guy called mike coderama, who explains the knapsack problem and provides code to solve it with dynamic programming. (There are some youtube videos i watched that explain it nicely using this method also). But this method is not recursive (so i coudn't count numcalls) like the Professor's MaxVal method (which i gave up trying to use to solve the problem)

http://dpaste.com/hold/552412/
^My code for problem set 8 (neated it up as best I could, and gave it a cool menu for the user to use to navigate through the functions!!)

http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-00-introduction-to-computer-science-and-programming-fall-2008/video-lectures/lecture-13/lec13.pdf
^Handout with the maxVal functions from lecture 13.

I stilll cant follow the recursive method that I think we were being pushed to implement.

http://dpaste.com/hold/552417/
^My attempt at trying to figure out how maxVal works(the simple one, not with memo)

I'd like to hear back from you,bwCA, and maybe check your solution aswell.

Answer 4

Here is my solution - If I remember correctly I used the example in the lecture and modified it to keep track of all the list indices that were chosen - not just the value.