package one

import (
	"bufio"
	"io"
)

func readLines(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
}