Learn Kotlin with the Kotlin Team: Advent of Code 2020 #9

In this episode of the Learn Kotlin with the Kotlin team series, we’ll look at different ways to manipulate lists in Kotlin to solve the puzzle.

Day 9: Encoding error
Explore different ways to manipulate lists in Kotlin using the ‘any’, ‘firstOrNull’, ‘firstNotNullOfOrNull’, ‘windowed’, ‘takeIf’, and ‘scan’ functions, which exemplify an idiomatic Kotlin style.

0:00 Intro
0:36 Puzzle Description
1:57 Solution, Part I
4:25 Finding invalid number
6:32 Using ‘windowed’
9:08 Part II
9:52 Solution, Part II

* Used with the permission of Advent of Code (Eric Wastl)

#Kotlin #Idiomatic #Tutorial #AdventOfCode #AdventOfCode2020 #AdventOfСodeInKotlin #Day9

[AlanDarkworld]

windowed() is a really neat function. I've found it particularly useful in algorithms that deal with a "current" and a "previous" element in the list. It is much clearer and less error prone than fiddling with the indices manually and carefully working around all corner cases.

[HtopSkills]

There are some functions in this video that I need to check out.

[cisimon]

Nice and neat solution, especially the improvement method of the second task, reminds of "integral image" from the viola jones face detection algorithm

[Marth]

perhaps we could immediately break the inner loop, when the 'subListSum' is greater than the 'targetSum', to avoid unnecessary calculations for the rest 'toIndex'es, right?

[pradyumnx]

🙏🏻Kotlin multiplateform mobile Beginners tutorial upload

[pradyumnx]

🙏🏻Kotlin multiplateform mobile Beginners tutorial upload

[pradyumnx]

🙏🏻Kotlin multiplateform mobile Beginners tutorial upload

[pradyumnx]

🙏🏻Kotlin multiplateform mobile Beginners tutorial upload