Step 2: The Main Loop & Adding Edges

We need to loop `N` times and read one command on each line. We'll use an `if/elif` block to determine the command type.

Guidance for Step 2

  • Main Loop: The loop should run for the total number of operations, which is stored in the variable `N`.
  • `add u v`: This is a **directed** edge. You need to access the adjacency list for user `u` and append user `v` to it.
  • Sorted Neighbors: The problem guarantees that for any user `u`, `add` commands will have `v` in increasing order. This means `adj[u]` will automatically be sorted! 
# Process all N operations
for _ in range(______):
    # Read the command line and split it
    line = input().split()
    if not line:
        continue

    cmd = line[0]

    if cmd == "add":
        u, v = int(line[1]), int(line[2])

        # Add a directed edge from u to v
        # The problem guarantees they come in sorted order!
        adj[______].append(______)

    elif cmd == "dfs":
        pass # We will fill this in next

    elif cmd == "bfs":
        pass # We will fill this in last
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