Tìm các node tham gia vào tam giác

from itertools import combinations

# Write a function that identifies all nodes in a triangle relationship with a given node.
def nodes_in_triangle(G, n):
    """
    Returns the nodes in a graph `G` that are involved in a triangle relationship with the node `n`.
    """
    triangle_nodes = set([n])

    # Iterate over all possible triangle relationship combinations
    for n1, n2 in ____:

        # Check if n1 and n2 have an edge between them
        if ____:

            # Add n1 to triangle_nodes
            ____

            # Add n2 to triangle_nodes
            ____

    return triangle_nodes

# Write the assertion statement
assert len(____(____, ____)) == ____