Practice Square Coding Question | Real Coding Interviews | Hack2hire

NewML System Design & SQL tracks just landedSee what's new

Question Bank Pricing Blog Forum

Quick Summary

Count character frequencies and initialize a leaf node for each unique character.
Sort nodes by ascending frequency, using lexicographical order as a tie-breaker.
Iteratively merge nodes by attaching the next character as the left child and the accumulated subtree as the right child.

What This Tests

Frequency analysis using hash maps
Multi-key custom sorting logic
Iterative tree construction and reference reassignment
Greedy merging strategies

Common Patterns

Hashing

Sorting

Greedy

Stdout

-