Advent of Code in Kotlin: Lessons Learned

An introduction to the Advent of Code and what I learned about solving puzzles in Kotlin.

Transcript

3. Photo by Elena Mozhvilo on Unsplash Photo by Markus Spiske on Unsplash
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16. 2020 Unofficial Advent of Code Survey - Jeroen Heijmans
18. Daniel Lin (@ephemient) Solved every daily puzzle in four different languages. ephemient.github.io/aoc2020/
19. Joris Portegies Zwart (@jorispz) Solves puzzles using Kotlin Multiplatform. github.com/jorispz/aoc-2020
20. Jakub Gwóźdź Solved every puzzle and provided a visualization. In Kotlin! jakubgwozdz.github.io/advent-of- code-2020/
21. Courtesy of @FuriousProgramm @FuriousProgramm Also attempting to solve this puzzle. Manually.
22. Since 2017, I have solved each puzzle each day, in Kotlin and blogged about it. https://todd.ginsberg.com
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25. val letters = listOf("A", "B", "C", "D") val numbers = listOf(1, 2, 3, 4)
26. val letters = listOf("A", "B", "C", "D") val numbers = listOf(1, 2, 3, 4) letters.zip(numbers) // [(A, 1), (B, 2), (C, 3), (D, 4)] // List<Pair<String,Int>>
27. val letters = listOf("A", "B", "C", "D")
28. val letters = listOf("A", "B", "C", "D") letters.zipWithNext() // [(A, B), (B, C), (C, D)] // List<Pair<String,String>>
29. val letters = listOf("A", "B", "C", "D")
30. val letters = listOf("A", "B", "C", "D") letters.chunked(2) // [[A, B], [C, D]] // List<List<String>>
31. val letters = listOf("A", "B", "C", "D", "E", "F")
32. val letters = listOf("A", "B", "C", "D", "E", "F") letters.windowed(3) // [[A, B, C], [B, C, D], [C, D, E], [D, E, F]] // List<List<String>>
33. val letters = listOf("A", "B", "C", "D", "E", "F") letters.windowed(3, 3) // [[A, B, C], [D, E, F]]
34. val letters = listOf("A", "B", "C", "D", "E", "F") letters.windowed(4, 4, false) // [[A, B, C, D]]
35. val theString = "Hello" theString.padEnd(7, '!') // Hello!!
36. val theString = "Hello" theString.padStart(7, '!') // !!Hello
37. val theString = "Left Right"
38. val theString = "Left Right" theString.substringBefore(" ") // "Left"
39. val theString = "Left Right" theString.substringBefore(" ") // "Left" theString.substringAfter(" ") // "Right"
40. val someList = listOf("A", "B", "C")
41. val someList = listOf("A", "B", "C") someList.any { it.length == 1 } // True!
42. val someList = listOf("A", "B", "C") someList.all { it.length == 1 } // True!
43. val someList = listOf("A", "B", "C") someList.none { it.length == 2 } // True!
44. "3".toInt() // 3
45. "3".toInt() // 3 '3'.toInt() // 51
46. fun Char.asInt(): Int = this.toString().toInt()
47. fun Char.asInt(): Int = this.toString().toInt() '3'.asInt() // 3
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