LeetCode/cs/find-all-possible-recipes-from-given-supplies.cs

public class Solution {
    public IList<string> FindAllRecipes(
        string[] recipes, IList<IList<string>> ingredients, string[] supplies
    ) {
        var available = new HashSet<string>(supplies);

        var indices = new Dictionary<string, int>();
        for (var i = 0; i < recipes.Length; ++i) {
            indices[recipes[i]] = i;
        }

        var dependencies = new Dictionary<string, List<string>>();
        var inDegree = new int[recipes.Length];

        foreach (var (idx, ingredient) in Enumerable.Range(0, recipes.Length).SelectMany(i => ingredients[i].Select(x => (i, x)))) {
            if (available.Contains(ingredient)) {
                continue;
            }

            dependencies.TryAdd(ingredient, []);
            dependencies[ingredient].Add(recipes[idx]);
            ++inDegree[idx];
        }

        var q = new Queue<int>(Enumerable.Range(0, recipes.Length).Where(i => inDegree[i] == 0));

        var created = new List<string>();
        while (q.TryDequeue(out var idx)) {
            var recipe = recipes[idx];
            created.Add(recipe);

            if (dependencies.TryGetValue(recipe, out var dependents)) {
                foreach (var dep in dependents) {
                    if (--inDegree[indices[dep]] == 0) {
                        q.Enqueue(indices[dep]);
                    }

                }
            }
        }

        return created;
    }
}