DSA · Theory

Iterative Depth First Traversal of Graph

Theory

244/810

Iterative Depth First Traversal of Graph

Iterative Depth First Traversal of Graph is a DSA topic. In plain words you use it for bus routes in a city map. Don’t start with a slogan — start with that picture.

Smallest example: BFS queue / DFS stack. Type it, run it, and say what you see. If you can do that from memory, you know Iterative Depth First Traversal of Graph.

From the example next to this theory: Iterative Depth First Traversal of Graph — dFS goes deep along a path before backtracking — natural with recursion/stack.

Trap — no visited set → infinite loop. Fix that before you talk about advanced DSA.

Viva — what is Iterative Depth First Traversal of Graph? Then show BFS queue / DFS stack. Then name the trap.

Exam tip

What is Iterative Depth First Traversal of Graph? Show this: BFS queue / DFS stack. Trap: no visited set → infinite loop.

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 — bus routes in a city map.
RuleBFS queue / DFS stack
Trapno visited set → infinite loop
Usea city map

DSA · Theory

Iterative Depth First Traversal of Graph

← All stacks

Theory

244/810

Iterative Depth First Traversal of Graph

Iterative Depth First Traversal of Graph is a DSA topic. In plain words you use it for bus routes in a city map. Don’t start with a slogan — start with that picture.

Smallest example: BFS queue / DFS stack. Type it, run it, and say what you see. If you can do that from memory, you know Iterative Depth First Traversal of Graph.

From the example next to this theory: Iterative Depth First Traversal of Graph — dFS goes deep along a path before backtracking — natural with recursion/stack.

Trap — no visited set → infinite loop. Fix that before you talk about advanced DSA.

Viva — what is Iterative Depth First Traversal of Graph? Then show BFS queue / DFS stack. Then name the trap.

Exam tip

What is Iterative Depth First Traversal of Graph? Show this: BFS queue / DFS stack. Trap: no visited set → infinite loop.

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 — bus routes in a city map.
RuleBFS queue / DFS stack
Trapno visited set → infinite loop
Usea city map

Iterative Depth First Traversal of Graph

Example

Short notes

Questions

Iterative Depth First Traversal of Graph

Example

Short notes

Questions