package one

import (
	"bufio"
	"io"
	"maps"
)

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

	scanner := bufio.NewScanner(r)
	for scanner.Scan() {
		graph.data = append(graph.data, scanner.Text())
	}

	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)
}

func firstPointFromMap(visited map[point]struct{}) point {
	for k := range maps.Keys(visited) {
		return k
	}
	panic("unable to fetch points from map")
}