aoc2024/day-06/internal/two/util.go

package two

import (
	"bufio"
	"io"
	"strings"
)

func parseLines(r io.Reader) (*graph, error) {
	graph := newGraph()

	count := 0
	scanner := bufio.NewScanner(r)
	for scanner.Scan() {
		line := scanner.Text()
		indx := strings.Index(line, "^")
		if indx != -1 {
			graph.startPoint = point{indx, count, N}
		}
		graph.data = append(graph.data, scanner.Text())

		for i, r := range line {
			if r == '#' {
				graph.obstacles = append(graph.obstacles, point{i, count, obstacle})
			}
		}

		count++
	}

	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)
}