Graph Algorithms Tutorial¶

cds.graph implements traversal, shortest paths, MST, topo sort, and cycle detection on a small Graph class.

1. Build a Graph¶

from cds.graph import Graph

g = Graph(directed=False)
for u, v, w in [("A", "B", 4), ("A", "C", 2), ("B", "C", 1), ("B", "D", 5), ("C", "D", 8)]:
    g.add_edge(u, v, weight=w)

2. Traversal¶

from cds.graph import bfs, dfs

print(bfs(g, "A"))
print(dfs(g, "A"))

3. Shortest Paths & MST¶

from cds.graph import dijkstra, kruskal_mst

print(dijkstra(g, "A"))  # {node: distance}
print(kruskal_mst(g))  # list of (u, v, weight)

4. Topological Sort & Cycles¶

from cds.graph import Graph, topological_sort, has_cycle

dag = Graph(directed=True)
dag.add_edge("a", "b")
dag.add_edge("b", "c")
print(topological_sort(dag))  # valid ordering
print(has_cycle(dag))  # False

Run the full demo with python examples/graph_demo.py.