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Islands in a graph using BFS

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Islands in a graph using BFS

Asha only reaches for Islands in a graph using BFS when bus routes has to stay correct in a city map.

Do Islands in a graph using BFS once by hand. BFS queue / DFS stack. Change one input. Say the new result out loud.

Islands in a graph using BFS exists so Asha can keep bus routes correct in a city map.

Islands in a graph using BFS shows up in a city map. Name bus routes, not “a real-world scenario”.

Islands in a graph using BFS miss — no visited set → infinite loop. Fix it before you talk about advanced DSA.

Islands in a graph using BFS is not a lonely heading. Asha ties it to bus routes.

Viva for Islands in a graph using BFS: what it is → BFS queue / DFS stack → the mistake (no visited set → infinite loop).

Exam tip

Say Islands in a graph using BFS in one breath, then BFS queue / DFS stack, then no visited set → infinite loop.

Example

from collections import deque

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

def bfs(start):
    seen, q = {start}, deque([start])
    order = []
    while q:
        u = q.popleft()
        order.append(u)
        for v in graph[u]:
            if v not in seen:
                seen.add(v)
                q.append(v)
    return order

print(bfs(1))

Islands in a graph using BFS — bFS explores level by level using a queue.

Short notes

DefIslands in a graph using BFS — Asha uses it for bus routes in a city map.
RuleIslands in a graph using BFS → BFS queue / DFS stack.
RememberIslands in a graph using BFS + time vs memory (a city map).
UseIslands in a graph using BFS in a city map (bus routes).
TrapIslands in a graph using BFS — no visited set → infinite loop.
ExIslands in a graph using BFS → bus routes.

from collections import deque graph = {1: [2, 3], 2: [4], 3: [], 4: []} def bfs(start): seen, q = {start}, deque([start]) order = [] while q: u = q.popleft() order.append(u) for v in graph[u]: if v not in seen: seen.add(v) q.append(v) return order print(bfs(1))

Islands in a graph using BFS

Example

Short notes

Questions

Islands in a graph using BFS

Example

Short notes

Questions