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Description for today’s challenge is here.
The description for the challenge is quite long and wordy, but ultimately there are only three things we need to remember:
- the total weight of packages need to be evenly divided into 3 groups
- the first group needs to have fewest packages possible
- given the same number of packages (fewest possible), the quantum entanglement (i.e. the product…) of the weights of packages in the first group needs to be the smallest possible
Based on these information, we can have the following:
For my input, all the weights are odd numbers, and the average weight is an even number. Which means we need an even number of packages in each group, furthermore, based on the input the smallest number of packages that can add up to the average weight is 6.
So rather than a brute force approach (which I tried and failed with) we can be smarter and:
- only consider the first group (since that’s all we need to answer the question)
- only consider groups of length 6
So, for each package, we will:
- yield the 6-package groups that can be formed with it
- yield the 6-package groups that can be formed without it
and we’ll short circuit a path if after collecting 6 packages in a group but the total weight of the group doesn’t add up to the average.
This is exactly what the following code snippet does, it returns all the 6-package groups that has a total weight equalling the average weight:
Finally, we just need to find the smallest quantum entanglement value of all the possible combinations:
Same approach as above, but slightly different setup.
Now that we’re dividing the total weight of all the packages by 4 instead of 3, the average is now an even number – meaning we’ll need an odd number of packages per group. Also, the smallest number of packages per group is now 5:
Hi, I’m Yan. I’m an AWS Serverless Hero and I help companies go faster for less by adopting serverless technologies successfully.
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.
Skill up your serverless game with this hands-on workshop.
My 4-week Production-Ready Serverless online workshop is back!
This course takes you through building a production-ready serverless web application from testing, deployment, security, all the way through to observability. The motivation for this course is to give you hands-on experience building something with serverless technologies while giving you a broader view of the challenges you will face as the architecture matures and expands.
We will start at the basics and give you a firm introduction to Lambda and all the relevant concepts and service features (including the latest announcements in 2020). And then gradually ramping up and cover a wide array of topics such as API security, testing strategies, CI/CD, secret management, and operational best practices for monitoring and troubleshooting.
If you enrol now you can also get 15% OFF with the promo code “yanprs15”.
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!
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.
- All you need to know about caching for serverless applications
- 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?
- Check-list for going live with API Gateway and Lambda
- How to choose the right API Gateway auth method
- CloudFormation protip: use !Sub instead of !Join
- AWS Lambda – should you have few monolithic functions or many single-purposed functions?
- Guys, we’re doing pagination wrong
- Top 10 Serverless framework best practices
- How to break the “senior engineer” career ceiling
- My advice to junior developers