Solution: The Number of the Smallest Unoccupied Chair

Discover how to assign the smallest unoccupied chair to friends arriving and leaving at different times by utilizing min heaps. Learn to efficiently manage chair allocation and release using priority queues, sort arrival times, and implement an optimized solution with O(n log n) complexity, preparing you for dynamic scheduling problems in coding interviews.

We'll cover the following...

Statement
Solution
- Time complexity
- Space complexity

Statement

At a party, $n$ friends, numbered from $0$ to $n - 1$ , arrive and leave at different times. There are infinitely many chairs, numbered $0$ onwards. Each arriving friend sits on the smallest available chair at that moment.

For example, if chairs $0$ , $1$ , and $5$ are occupied when a friend arrives, they will sit on chair number $2$ .

When a friend leaves, their chair becomes immediately available. If another friend arrives simultaneously, they can take that chair.

You are given a $0$ -indexed $2D$ list ...