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Coding & Algorithms questions require understanding of core concepts and practice. PracHub provides solutions with explanations to help you master coding & algorithms interviews.

What difficulty level is this interview question?

This is a hard difficulty Coding & Algorithms question, commonly asked during Onsite rounds at Zest.

What role is this question designed for?

This question is commonly asked for Data Scientist candidates at Zest during technical interviews.

Compute tree depth and meeting rooms | Zest Interview Question

Quick Overview

This question evaluates skills in tree traversal and recursion for computing maximum depth of a binary tree, alongside interval scheduling and resource allocation for determining the minimum number of meeting rooms, testing reasoning about data structures such as trees and interval endpoints.

Solve both coding problems.

Problem 1: Maximum depth of a binary tree

Given the root of a binary tree, return its maximum depth. The maximum depth is the number of nodes on the longest path from the root node down to a leaf node.

Assumptions:

If the tree is empty, return 0.
The tree may be highly unbalanced.
The number of nodes can be up to 100,000, so consider recursion-depth limitations depending on the language.

Example: Input tree: 3, 9, 20, null, null, 15, 7 Output: 3

Problem 2: Minimum meeting rooms

Given an array of meeting time intervals intervals, where each interval is [start, end), return the minimum number of conference rooms required so that all meetings can be held.

Assumptions:

start < end for every meeting.
Times are integers.
Intervals are half-open, so a meeting ending at time 10 does not conflict with another meeting starting at time 10 .
The number of intervals can be up to 100,000.

Example: Input: [[0, 30], [5, 10], [15, 20]] Output: 2

Example: Input: [[7, 10], [10, 12]] Output: 1

Quick Overview

Problem 1: Maximum depth of a binary tree

Given the root of a binary tree, return its maximum depth. The maximum depth is the number of nodes on the longest path from the root node down to a leaf node.

Assumptions:

If the tree is empty, return 0.

The tree may be highly unbalanced.

The number of nodes can be up to 100,000, so consider recursion-depth limitations depending on the language.

Example: Input tree: 3, 9, 20, null, null, 15, 7 Output: 3

Problem 2: Minimum meeting rooms

Given an array of meeting time intervals intervals, where each interval is [start, end), return the minimum number of conference rooms required so that all meetings can be held.

Assumptions:

start < end for every meeting.

Times are integers.

Intervals are half-open, so a meeting ending at time 10 does not conflict with another meeting starting at time 10 .

The number of intervals can be up to 100,000.

Example: Input: [[0, 30], [5, 10], [15, 20]] Output: 2

Example: Input: [[7, 10], [10, 12]] Output: 1

Compute tree depth and meeting rooms

Quick Overview

Problem 1: Maximum depth of a binary tree

Problem 2: Minimum meeting rooms

Comments (0)

Compute tree depth and meeting rooms

Quick Overview

Problem 1: Maximum depth of a binary tree

Problem 2: Minimum meeting rooms

Comments (0)