package d6

import "strings"

// Inspired by
// https://www.reddit.com/r/adventofcode/comments/r9z49j/comment/hnfaisu/?utm_source=share&utm_medium=web2x&context=3
func P2(input string, startDays int) int {
	fishes := toNum(strings.Split(strings.TrimSpace(input), ","))
	ages := make([]int, 9)

	for _, fish := range fishes {
		ages[fish]++
	}

	for day := 0; day < startDays; day++ {
		dieToday := ages[0]
		ages = ages[1:]
		ages[6] += dieToday
		ages = append(ages, dieToday)
	}

	sum := 0
	for _, age := range ages {
		sum += age
	}

	return sum
}