[Solved] Identify the error in this state transition logic for a system with states idle, moving up, and moving down: if state == 'idle' and event == 'move up':... | LLD

LLD - Design — Elevator System

Identify the error in this state transition logic for a system with states idle, moving up, and moving down:

if state == 'idle' and event == 'move up':
    state = 'moving up'
elif state == 'moving up' and event == 'move down':
    state = 'moving down'
elif state == 'moving down' and event == 'stop':
    state = 'idle'

AMissing transition from idle to moving down

BMissing transition from idle to moving up

CIncorrect event name for stopping

DState variable is not updated

Step-by-Step Solution

Solution:

Step 1: Review all possible transitions
The code allows idle to moving up, moving up to moving down, and moving down to idle, but no direct transition from idle to moving down.
Step 2: Identify missing transitions
Since the system should allow moving down from idle, this transition is missing.
Final Answer:
Missing transition from idle to moving down -> Option A
Quick Check:
Check all valid transitions included [OK]

Quick Trick: Check if all state-event pairs have transitions [OK]

Common Mistakes:

MISTAKES

Assuming moving up can switch directly to moving down
Ignoring missing transitions from idle
Confusing event names with states

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Identify the error in this state transition logic for a system with states idle, moving up, and moving down:

Step 1: Review all possible transitions

Step 2: Identify missing transitions

Final Answer:

Quick Check:

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