aoc2024/day-20/internal/two/util.go

package two

import (
	"bufio"
	"io"
	"strings"

	"github.com/onyx-and-iris/aoc2024/day-20/internal/point"
)

func parseLines(r io.Reader) (*graph, error) {
	graph := newGraph(make([]string, 0))

	var linecount int
	scanner := bufio.NewScanner(r)
	for scanner.Scan() {
		line := scanner.Text()

		if strings.Contains(line, "S") {
			indx := strings.Index(line, "S")
			graph.start = point.New(indx, linecount)
		}
		if strings.Contains(line, "E") {
			indx := strings.Index(line, "E")
			graph.end = point.New(indx, linecount)
		}

		graph.data = append(graph.data, line)

		linecount++
	}

	if err := scanner.Err(); err != nil {
		return nil, err
	}

	return graph, nil
}

func replaceAtIndex(s string, r rune, i int) string {
	out := []rune(s)
	out[i] = r
	return string(out)
}