59 lines
1.4 KiB
Go
59 lines
1.4 KiB
Go
package main
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import (
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"bufio"
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"fmt"
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"os"
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"regexp"
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"strconv"
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)
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func main() {
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rules := map[string]map[string]int{}
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mainColorRe := regexp.MustCompile(`^(?P<color>\w+ \w+) bags contain (?P<contents>.*)\.$`)
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contentRe := regexp.MustCompile(`(?P<amount>\d+) (?P<color>\w+ \w+) bags?`)
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file, _ := os.Open("input.txt")
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defer file.Close()
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for scanner := bufio.NewScanner(file); scanner.Scan(); {
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text := scanner.Text()
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rule := map[string]int{}
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for _, c := range contentRe.FindAllString(mainColorRe.ReplaceAllString(text, "$contents"), -1) {
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rule[contentRe.ReplaceAllString(c, "$color")], _ = strconv.Atoi(contentRe.ReplaceAllString(c, "$amount"))
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}
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rules[mainColorRe.ReplaceAllString(text, "$color")] = rule
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}
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fmt.Println("Part 1:", len(unique(containedIn("shiny gold", rules))))
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fmt.Println("Part 2:", numberOfBags("shiny gold", rules)-1)
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}
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func containedIn(target string, rules map[string]map[string]int) (colors []string) {
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for k, r := range rules {
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if _, has := r[target]; has {
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colors = append(colors, append(containedIn(k, rules), k)...)
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}
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}
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return
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}
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func unique(s []string) (list []string) {
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k := map[string]bool{}
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for _, e := range s {
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if _, has := k[e]; !has {
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k[e] = true
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list = append(list, e)
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}
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}
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return
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}
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func numberOfBags(target string, rules map[string]map[string]int) int {
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bags := 1
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for color, amount := range rules[target] {
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bags += amount * numberOfBags(color, rules)
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}
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return bags
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}
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