Design Data Structure for Sparse Matrices Operations
Company: Pinterest
Role: Data Scientist
Category: Coding & Algorithms
Difficulty: medium
Interview Round: Onsite
##### Scenario
Analytics engine stores extremely sparse numeric matrices.
##### Question
Design a data structure to store two sparse matrices and implement print(), add(A,B) and multiply(A,B). Discuss complexity for each operation.
##### Hints
Use dictionary-of-keys or CSR; pre-index rows and columns to speed multiplication.
Quick Answer: This question evaluates a candidate's ability to design efficient data structures and implement algorithms for sparse matrix storage and operations, emphasizing space-efficient representations, matrix arithmetic, and computational complexity reasoning.