The Beer Money Problem - MLUG Coding Challenge (Intro)

I like a good coding challenge, and this one is particularly fun. It was set by the wonderful folks at MLUG and goes like this:

I went to the supermarket to get some beers for the Euros final and my bill came to £11.99. With the money detailed [below], how many combinations are there that make up the exact change to pay my bill? 

 

Coin/Note	Quantity	Sub Total
£      10.00	1	£    10.00
£        5.00	1	£       5.00
£        2.00	4	£       8.00
£        1.00	5	£       5.00
£        0.50	3	£       1.50
£        0.20	6	£       1.20
£        0.10	4	£       0.40
£        0.05	3	£       0.15
£        0.02	10	£       0.20
£        0.01	5	£       0.05
Total	42	£    31.50

Now's a great time to open up LabVIEW and try it out - see if you can get an answer!

I actually spent a good week of evenings hunched over my (paper) notebook and computer playing with different approaches. Some of my colleagues had a go too, and it was interesting to see the different ways we had of solving it.

In Post 1 I will talk about my first simple approach, then Post 2 how I made it recursive, and Post 3 other approaches. I'm hoping to speak about this briefly at the next MLUG - will put up a link if it gets in.

Cheers,

Leah