d, err := parseInput("input.txt")

	d, err := parseInput("input.test")

	s := seen{}
	for len(s) < len(road)*len(road[0]) {
		road.update(s, d, road.getLowest(s))

	opts := seen{point{0, 1}: true, point{1, 0}: true}
	for len(opts) > 0 {
		next := road.getLowest(opts)
		road.update(d, next, opts)

func (r distance) update(s seen, dist distance, p point) {
	s[p] = true

func (r distance) update(dist distance, p point, opts seen) {
	delete(opts, p)

				opts[point{diffrow, diffcol}] = true

func (r distance) getLowest(s seen) point {

func (r distance) getLowest(opts seen) point {

	for row := 0; row < len(r); row++ {
		for col := 0; col < len(r[0]); col++ {
			if s[point{row, col}] {
				continue
			}
			if r[row][col] < min {
				min = r[row][col]
				ret = point{row, col}
			}

	for o := range opts {
		if r[o[0]][o[1]] < min {
			ret = o
			min = r[o[0]][o[1]]