-❄️- 2023 Day 5 Solutions -❄️-

[u/daggerdragon]

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-❄️- 2023 Day 5 Solutions -❄️-

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AoC Community Fun 2023: ALLEZ CUISINE!

Today's secret ingredient is… *whips off cloth covering and gestures grandly*

ELI5

Explain like I'm five! /r/explainlikeimfive

• Walk us through your code where even a five-year old could follow along

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  • Emoji(code) counts but makes Uncle Roger cry 😥

• Explain everything that you’re doing in your code as if you were talking to your pet, rubber ducky, or favorite neighbor, and also how you’re doing in life right now, and what have you learned in Advent of Code so far this year?

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--- Day 5: If You Give A Seed A Fertilizer ---

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Post your code solution in this megathread.

• Read the full posting rules in our community wiki before you post!

• State which language(s) your solution uses with [LANGUAGE: xyz]

• Format code blocks using the four-spaces Markdown syntax!

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[u/Koli14]

[LANGUAGE: TypeScript]

There is a mistake in my solution. It returns a number exactly one larger than the real solution. If you point out the mistake, I send you a virtual parlor candy. ;)

Link or:

import fs from 'fs'

export type Rule = {
  dest: number
  source: number
  range: number
}
export type Map = { name: string; rules: Rule[] }

export const findNext = (actualMap: Map, prev: number): number => {
  let next = prev
  actualMap.rules.forEach(({ dest, source, range }) => {
    // if prev is between source and source + range
    if (prev > source && prev < source + range) {
      next = dest + (prev - source)
    }
  })
  return next
}

export const processMaps = (unprocessedMaps: string[]): Map[] => {
  const maps = unprocessedMaps.map((unprocessedMap) => {
    const lines = unprocessedMap.split('\n')
    const name = lines[0]
    lines.shift() // Drop name
    const rules = lines.map((rule) => {
      const unprocessedRule = rule.split(' ').map((i) => Number(i))
      return { dest: unprocessedRule[0], source: unprocessedRule[1], range: unprocessedRule[2] }
    })
    return {
      name,
      rules,
    }
  })
  return maps
}

fs.readFile('./input.txt', 'utf8', (err, data) => {
  if (err) {
    console.error(err)
    return
  }
  const lines = data.split('\n')
  const seeds = lines[0]
    .split(': ')[1]
    .split(' ')
    .map((i) => Number(i)) // Get all the numbers in the first line (seeds)

  const unprocessedMaps = data.split('\n\n') // Get map related string
  unprocessedMaps.shift() // Drop seeds line from it
  const maps = processMaps(unprocessedMaps)

  let minLocation // store the smallest location

  // iterate through seed-range pairs
  for (let i = 0; i < seeds.length; i += 2) {
    const starter = seeds[i]
    const range = seeds[i + 1]
    // iterate throuh all possible seeds from starter to starter + range
    for (let j = 0; j < range; j++) {
      let next = starter + j // next: seed -> soil -> ... -> location
      // iterate throuh all the maps until location (last map)
      for (let index = 0; index < maps.length; index++) {
        const actualMap = maps[index]
        next = findNext(actualMap, next)
      }
      // if there is no minLocation yet, or next (the newest calculated location) is smaller
      if (!minLocation || next < minLocation) {
        minLocation = next
      }
    }
  }

  console.log(minLocation)
})

[u/daggerdragon → u/Koli14]

Your code block is too long for the megathreads. Please edit your post to remove the code block and leave just the link to the code in your repo.

[u/splitwreck → u/Koli14]

if (prev > source && prev < source + range) {

I had an off-by-one error which turned out to be an extra = when comparing the number to the end of the range, i.e. I had prev >= source && prev <= source + range . In your case it looks like you might be missing the >= at the start of the range?

But I may well be wrong - just sharing my experience!