Algorithms and Data Structures

public sealed class Channel<T> {
  // Use a thread-safe data store to free us from locking semantics for any
  // number of producers and consumers.
  private readonly ConcurrentQueue<T> _items = new ConcurrentQueue<T>();

  // A mechanism for coordinating between producers and consumers.
  private readonly SemaphoreSlim _semaphore = new Semaphore(0);

  public void Write(T item)
  {
    _items.Enqueue(item); // Store the data.
    _semaphore.Release(); // Notify any consumers that more data is available.
  }

  public ValueTask<T> ReadAsync(CancellationToken ct = default)
  {
    await _semaphore.WaitAsync(ct).ConfigureAwait(false); // Wait for data to be available.
    bool gotOne = _items.TryDequeue(out T item);
    Debug.Assert(gotOne);
    return item;
  }
}

def num_satisfied_children(greeds: List[int], cookies: List[int]) -> int:
  greeds.sort()
  cookies.sort()

  count = 0
  g_idx, c_idx = 0, 0
  while g_idx < len(greeds) and c_idx < len(cookies):
    if cookies[c_idx] >= greeds[g_idx]:
      count += 1
      g_idx += 1

    c_idx += 1

  return count