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Graphs as Friendship Maps

The analogy

🧸 ELI5⚙ Tech

A friendship map is messier than an org chart: friendship goes both ways, circles loop back on each other, and there is no single person at the top. A graph is just dots (people) joined by lines (relationships).

Visualizer

Dots, lines and loops

step 1 / 6

Eight dots, ten lines. No root, no hierarchy — just relationships.V = 8, E = 10

🎯 Predict modespeed1×

PythonJavaScriptHow devs thinkWhere it's used

adj = {
    "A": ["B", "C"],
    "B": ["A", "D", "E"],
    "C": ["A", "F", "G"],
}

len(adj["B"])        # degree of B
"C" in adj["A"]      # is there an edge?
# space O(V + E) — right for sparse graphs

Check yourself

A tree is…