aoc2024/day-02/internal/two/solve.go

package two

import (
	"bufio"
	"bytes"
	"io"

	"github.com/onyx-and-iris/aoc2024/day-02/internal/util"
)

type comparator func([]int, int) bool

func Solve(data []byte) (int, error) {
	r := bytes.NewReader(data)
	sum := parseLines(r)

	return sum, nil
}

func parseLines(r io.Reader) int {
	var sum int

	scanner := bufio.NewScanner(r)
	for scanner.Scan() {
		nums := util.IntsFromString(scanner.Text())

		cmpIncrease := func(nums []int, i int) bool {
			return nums[i-1] >= nums[i]
		}
		cmpDecrease := func(nums []int, i int) bool {
			return nums[i-1] <= nums[i]
		}

		if check(withComparator, nums, cmpIncrease) || check(withComparator, nums, cmpDecrease) {
			sum++
		}
	}

	return sum
}

func check(fn func([]int, comparator, int) bool, nums []int, comparator comparator) bool {
	var count int
	return fn(nums, comparator, count)
}