aoc2023/day-5/util.go

package main

import (
	"bufio"
	"os"
	"regexp"
	"strconv"
	"strings"
	"unicode"

	log "github.com/sirupsen/logrus"
)

// readlines reads lines from stdin.
// Then it returns them as an array of strings
func readlines() []string {
	lines := []string{}

	scanner := bufio.NewScanner(os.Stdin)
	for scanner.Scan() {
		lines = append(lines, scanner.Text())
	}

	if err := scanner.Err(); err != nil {
		log.Fatal(err)
	}

	return lines
}

var r = regexp.MustCompile(`([\w-]+) map[:]`)

// parseLines parses input to a data map
func parseLines(lines []string) {
	f := func(c rune) bool {
		return !unicode.IsDigit(c)
	}

	seeds = convertToInts(strings.FieldsFunc(lines[0], f))

	for i := 2; i < len(lines); i++ {
		m := r.FindStringSubmatch(lines[i])
		if len(m) == 2 {
			identifiers = append(identifiers, m[1])
			for i = i + 1; i < len(lines) && len(lines[i]) != 0; i++ {
				d := newData(convertToInts(strings.FieldsFunc(lines[i], f))...)
				dataMap[m[1]] = append(dataMap[m[1]], d)
			}
		}
	}
	log.Debug(identifiers)
}

// convertToInts converts a string representing ints to an array of ints
func convertToInts(data []string) []int {
	nums := []int{}
	for _, elem := range data {
		n, _ := strconv.Atoi(elem)
		nums = append(nums, n)
	}
	return nums
}

// isOverlapping returns true if two ranges overlap. see:
// https://stackoverflow.com/questions/325933/determine-whether-two-date-ranges-overlap/325964#325964
func isOverlapping(maxStart, minEnd int) bool {
	return maxStart < minEnd
}