In England the currency is made up of pound, £, and pence, p, and there are eight coins in general circulation:
1p, 2p, 5p, 10p, 20p, 50p, £1 (100p) and £2 (200p).
It is possible to make £2 in the following way:
1x£1 + 1x50p + 2x20p + 1x5p + 1x2p + 3x1p
How many different ways can £2 be made using any number of coins?
// the total and available coins let total, coins = 200, [1;2;5;10;20;50;100;200] // implement the coin change algorithm let rec count n m = if n = 0 then 1 else if n < 0 then 0 else if (m <= 0 && n >= 1) then 0 else (count n (m-1)) + (count (n-coins.[m-1]) m) let answer = count total coins.Length
Not much for me to add here really, see here for the coin change algorithm which I’ve used in my solution.
I’m an AWS Serverless Hero and the author of Production-Ready Serverless. I have run production workload at scale in AWS for nearly 10 years and I have been an architect or principal engineer with a variety of industries ranging from banking, e-commerce, sports streaming to mobile gaming. I currently work as an independent consultant focused on AWS and serverless.
Here is a complete list of all my posts on serverless and AWS Lambda. In the meantime, here are a few of my most popular blog posts.
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