adventofcode/2024/01/main.go

package main

import (
	"aoc2024/helper"
	"fmt"
	"sort"
)

var list_a, list_b []int

func main() {
	list_a, list_b = helper.ReadLinesTwoIntSlices()

	// part 1
	distance := list_distance(list_a, list_b)
	fmt.Printf("Distance: %v\n", distance)

	// part 2
	similarity := list_similarity(list_a, list_b)
	fmt.Printf("Similarity: %v\n", similarity)
}

func list_distance(list_a []int, list_b []int) (dist int) {
	sort.Ints(list_a)
	sort.Ints(list_b)

	for i := range list_a {
		dist += helper.Abs(list_a[i] - list_b[i])
	}
	return dist
}

func list_similarity(list_a []int, list_b []int) (sim int) {
	for _, val := range list_a {
		valcount := countIntInList(list_b, val)
		sim += valcount * val
	}
	return sim
}

func countIntInList(lst []int, i int) (count int) {
	for _, val := range lst {
		if val == i {
			count++
		}
	}
	return count
}