DSA · Theory

Iterative Depth First Traversal of Graph

Theory

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Iterative Depth First Traversal of Graph

Iterative Depth First Traversal of Graph is simple if you keep it on paper. Meera uses it for bus routes in a city map.

Iterative Depth First Traversal of Graph on the board: BFS queue / DFS stack. Then say what bus routes looks like after.

Skip Iterative Depth First Traversal of Graph and no visited set → infinite loop shows up in a city map.

Use Iterative Depth First Traversal of Graph when bus routes must stay clear. If a simpler DSA step works, use that instead.

Iterative Depth First Traversal of Graph miss: no visited set → infinite loop. Fix it before you talk about advanced DSA.

Place Iterative Depth First Traversal of Graph next to nearby DSA work — BFS queue / DFS stack is the link.

Close Iterative Depth First Traversal of Graph with: “If I skip it, bus routes goes wrong like this: no visited set → infinite loop.”

Exam tip

For Iterative Depth First Traversal of Graph: definition + a city map + one failure.

Example

graph = {1: [2, 3], 2: [4], 3: [], 4: []}

def dfs(u, seen=None):
    if seen is None:
        seen = set()
    seen.add(u)
    order = [u]
    for v in graph[u]:
        if v not in seen:
            order += dfs(v, seen)
    return order

print(dfs(1))

Iterative Depth First Traversal of Graph — dFS goes deep along a path before backtracking — natural with recursion/stack.

Short notes

DefIterative Depth First Traversal of Graph — Meera uses it for bus routes in a city map.
RuleIterative Depth First Traversal of Graph → BFS queue / DFS stack.
RememberIterative Depth First Traversal of Graph + a dry-run table (a city map).
UseIterative Depth First Traversal of Graph in a city map (bus routes).
TrapIterative Depth First Traversal of Graph — no visited set → infinite loop.
ExIterative Depth First Traversal of Graph → bus routes.

graph = {1: [2, 3], 2: [4], 3: [], 4: []} def dfs(u, seen=None): if seen is None: seen = set() seen.add(u) order = [u] for v in graph[u]: if v not in seen: order += dfs(v, seen) return order print(dfs(1))

Iterative Depth First Traversal of Graph

Example

Short notes

Questions

Iterative Depth First Traversal of Graph

Example

Short notes

Questions