Summary

An adjacency_list is a graph_representation that stores each vertex’s vertex_neighbors. Its space_complexity is O_V_plus_E, so it suits sparse_graphs. Neighbor iteration is efficient; you visit each neighbor once. Checking an edge can take time proportional to the vertex degree. It supports directed_graphs and undirected graphs. For weights, store (neighbor, weight) pairs for weighted_edges. Common implementations use arrays or vectors of lists or hash maps.