Which of the following algorithmic changes correctly adapts the solution to handle this variant efficiently?
hard🎤 Interviewer Follow-up Q15 of Q15
Intervals - Car Pooling
Suppose the car pooling problem is modified so that trips can overlap and passengers can be picked up and dropped off multiple times (i.e., trips can reuse the same passengers). Which of the following algorithmic changes correctly adapts the solution to handle this variant efficiently?
AUse a segment tree or binary indexed tree to efficiently update and query passenger counts over intervals
BSwitch to a priority queue to process events in order and track current passengers dynamically
CUse the same difference array approach but multiply passenger counts by the number of trips to simulate reuse
DModify the difference array to allow negative passenger counts and track net changes carefully
Step-by-Step Solution
Solution:
Step 1: Understand reuse complexity
Reusing passengers means overlapping intervals can increase and decrease counts multiple times, requiring efficient range updates and queries.
Step 2: Identify suitable data structure
Segment trees or binary indexed trees support efficient interval updates and queries, handling overlapping intervals with reuse.
Final Answer:
Option A -> Option A
Quick Check:
Segment trees handle dynamic interval sums efficiently [OK]
Quick Trick:Reuse -> need data structure for interval updates [OK]
