aoc24/day2/main.go

package main

import (
	"fmt"
	"strconv"
	"strings"

	"git.mstar.dev/mstar/aoc24/util"
	"git.mstar.dev/mstar/goutils/maputils"
	"git.mstar.dev/mstar/goutils/other"
	"git.mstar.dev/mstar/goutils/sliceutils"
)

func parseLine(line string) []int {
	strElems := sliceutils.Filter(
		strings.Split(line, " "),
		func(t string) bool { return len(t) > 0 },
	)
	return sliceutils.Map(strElems, func(t string) int {
		return other.Must(strconv.Atoi(t))
	})
}

// This is ugly. I'm sure there is a way to use some cool filter for when to exclude something
// or not. But I'm not smart enough for that
func generateCombinations(in []int) [][]int {
	variations := [][]int{in}

	for pos := range len(in) {
		tmp := []int{}
		for i, v := range in {
			if i == pos {
				continue
			}
			tmp = append(tmp, v)
		}
		variations = append(variations, tmp)
	}

	return variations
}

func isSafe(in []int) bool {
	isIncrementing := in[0] < in[1]
	lastVal := in[0]
	for _, elem := range in[1:] {
		if util.AbsI(elem-lastVal) > 3 {
			return false
		}
		if elem-lastVal == 0 {
			return false
		}
		if isIncrementing && elem < lastVal || !isIncrementing && elem > lastVal {
			return false
		}
		lastVal = elem
	}
	return true
}

func main() {
	lines := util.FileContentToNonEmptyLines(util.LoadFileFromArgs())
	safeLines1 := map[int]bool{}

	for i, line := range lines {
		elems := parseLine(line)
		safeLines1[i] = isSafe(elems)
	}
	filteredTask1 := maputils.FilterMap(safeLines1, func(k int, v bool) bool {
		return v
	})
	fmt.Printf("Task 1: %d\n", len(filteredTask1))

	safeLines2 := map[int]bool{}
	for i, line := range lines {
		elems := parseLine(line)
		variations := generateCombinations(elems)
		for _, variation := range variations {
			if isSafe(variation) {
				safeLines2[i] = true
			}
		}
	}
	filteredTask2 := maputils.FilterMap(safeLines2, func(k int, v bool) bool {
		return v
	})
	fmt.Printf("Task 2: %d\n", len(filteredTask2))
}

/* for _, elem := range elems[1:] {
	if util.AbsI(elem-lastVal) > 3 {
		// fmt.Printf("Line %d failed max diff with a value of %d\n", i, util.AbsI(elem-lastVal))
		if !firstDiscordDone {
			// fmt.Printf("Discard for line %d used up\n", i)
			firstDiscordDone = true
			continue
		}
		fmt.Printf("Line %d failed max diff with a value of %d\n", i, util.AbsI(elem-lastVal))
		log.Printf("%d: %s\n", i, line)
		continue lineloop2
	}
	if elem-lastVal == 0 {
		// fmt.Printf("Line %d failed no equal vals\n", i)
		if !firstDiscordDone {
			// fmt.Printf("Discard for line %d used up\n", i)
			firstDiscordDone = true
			continue
		}
		log.Printf("%d: %s\n", i, line)
		fmt.Printf("Line %d failed no equal vals\n", i)
		continue lineloop2
	}
	if isInc && elem < lastVal || !isInc && elem > lastVal {
		// fmt.Printf("Line %d failed same directionm\n", i)
		if !firstDiscordDone {
			// fmt.Printf("Discard for line %d used up\n", i)
			firstDiscordDone = true
			continue
		}
		log.Printf("%d: %s\n", i, line)
		fmt.Printf("Line %d failed same directionm\n", i)
		continue lineloop2
	}
	lastVal = elem
}
*/