aoc2024/day-12/internal/two/explore.go

package two

import "github.com/onyx-and-iris/aoc2024/day-12/internal/queue"

func exploreAreaSequentially(start point, graph *graph) path {
	queue := queue.New[point]()
	queue.Enqueue(start)
	visited := make(map[point]struct{})
	var perimeter int

	for !queue.IsEmpty() {
		current := queue.Dequeue()

		_, ok := visited[current]
		if ok {
			continue
		}
		visited[current] = struct{}{}

		for _, n := range neighbours(current) {
			if graph.isOutOfBounds(n) {
				perimeter++
				continue
			}

			if graph.valueAt(n) != graph.valueAt(current) {
				perimeter++
				continue
			}
			queue.Enqueue(n)
		}
	}

	return path{visited, perimeter}
}