You can become a serverless blackbelt. Enrol in my course Learn you some Lambda best practice for great good! and learn best practices for performance, cost, security, resilience, observability and scalability. By the end of this course, you should be able to make informed decisions on which AWS service to use with Lambda and how to build highly scalable, resilient and cost-efficient serverless applications.
Using names.txt (right click and ‘Save Link/Target As…’), a 46K text file containing over five-thousand first names, begin by sorting it into alphabetical order. Then working out the alphabetical value for each name, multiply this value by its alphabetical position in the list to obtain a name score.
For example, when the list is sorted into alphabetical order, COLIN, which is worth 3 + 15 + 12 + 9 + 14 = 53, is the 938th name in the list. So, COLIN would obtain a score of 938 x 53 = 49714.
What is the total of all the name scores in the file?
open System.IO let values = File.ReadAllLines(@"C:\TEMP\names.txt") |> Array.map (fun s -> s.Replace("\"", "")) |> Array.collect (fun s -> s.Trim().Split(',')) |> Array.sort |> Array.map (fun s -> s.ToUpper().ToCharArray() |> Array.sumBy (fun c -> int32(c) - (int32('A') - 1))) let answer = Array.map2 (fun v p -> v * p) values [|1..values.Length|] |> Array.sum
Once I’ve downloaded the names.txt file and loaded its contents in, the first thing I needed to do was to remove the double quotes and split the remaining strings by comma to get back a string array of the names, e.g.:
[“MARY”; “PATRICIA”; …]
Now that the data is in a useful format I can easily sort it and then do the necessary computation to work out the score for each name. Let me draw your attention to the function in the Array.sumBy function:
Array.sumBy (fun c -> int32(c) - (int32('A') - 1))
As I’ve mentioned in the problem 8 solution, int32(char) returns the unicode value of the char, which in this case is the alphabetical value we need to calculate the score for a name. But we can’t just use it as it is, because the char sequence A, B, C… does not start at 1, which is why we need to work out the offset using int32(‘A’) – 1.
Finally, the Array.map2 function is similar to Array.map, except that it works on two arrays at a time. So here I’m transforming the array of alphabetical values (for the sorted names) and the array of corresponding alphabetical orders into the score for each name before I add them all up to get the answer.
I specialise in rapidly transitioning teams to serverless and building production-ready services on AWS.
Are you struggling with serverless or need guidance on best practices? Do you want someone to review your architecture and help you avoid costly mistakes down the line? Whatever the case, I’m here to help.
Check out my new podcast Real-World Serverless where I talk with engineers who are building amazing things with serverless technologies and discuss the real-world use cases and challenges they face. If you’re interested in what people are actually doing with serverless and what it’s really like to be working with serverless day-to-day, then this is the podcast for you.
Check out my new course, Learn you some Lambda best practice for great good! In this course, you will learn best practices for working with AWS Lambda in terms of performance, cost, security, scalability, resilience and observability. We will also cover latest features from re:Invent 2019 such as Provisioned Concurrency and Lambda Destinations. Enrol now and start learning!
Check out my video course, Complete Guide to AWS Step Functions. In this course, we’ll cover everything you need to know to use AWS Step Functions service effectively. There is something for everyone from beginners to more advanced users looking for design patterns and best practices. Enrol now and start learning!
Are you working with Serverless and looking for expert training to level-up your skills? Or are you looking for a solid foundation to start from? Look no further, register for my Production-Ready Serverless workshop to learn how to build production-grade Serverless applications!
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.
- Lambda optimization tip – enable HTTP keep-alive
- You are wrong about serverless and vendor lock-in
- You are thinking about serverless costs all wrong
- Just how expensive is the full AWS SDK?
- Many faced threats to Serverless security
- We can do better than percentile latencies
- Yubl’s road to Serverless
- AWS Lambda – should you have few monolithic functions or many single-purposed functions?
- AWS Lambda – compare coldstart time with different languages, memory and code sizes
- Guys, we’re doing pagination wrong
- Top 10 Serverless framework best practices