aoc2023/day-4/one.go

package main

import (
	"regexp"
)

type M map[string]interface{}

var allCards []M

var _regex_winning_numbers = regexp.MustCompile(
	`^Card (?P<card>[\s\d]+):\s` +
		`(?P<winning>[0-9\s]+)\s` +
		`\|\s` +
		`(?P<mynums>[0-9\s]+)$`)

var _regex_nums = regexp.MustCompile("[0-9]+")

// compareLists returns the number of matching elements between winning and mynums
func compareLists(winningStr string, mynumsStr string) (int, error) {
	x, err := numStrToArr(winningStr, []int{})
	if err != nil {
		return 0, err
	}
	winning := x
	x, err = numStrToArr(mynumsStr, []int{})
	if err != nil {
		return 0, err
	}
	mynums := x

	n := 0
	for _, num := range mynums {
		if contains(winning, num) {
			n += 1
		}
	}
	return n, nil
}

// one computes points based on matching numbers
func one(lines []string) (int, error) {
	for _, line := range lines {
		parseAllCards(line)
	}
	cards = make([]Card, len(lines))

	sum := 0
	for x, card := range allCards {
		m, err := compareLists(card["winning"].(string), card["mynums"].(string))
		if err != nil {
			return 0, err
		}
		cards[x].matches = m
		if cards[x].matches > 0 {
			sum += (pow(2, cards[x].matches-1))
		}
	}

	return sum, nil
}