Search⌘ K
AI Features
Home
Courses
Grokking the Coding Interview Patterns

Solution: Snapshot Array

Explore how to implement a Snapshot Array that supports setting values, taking snapshots, and retrieving values from snapshots. Understand both naive and optimized approaches using nested dictionaries to efficiently store state changes and improve memory usage. Learn to apply custom data structures for scalable and efficient coding interview solutions.

We'll cover the following...

Statement

In this challenge, you have to implement a Snapshot Array with the following properties:

  • Constructor (length): This is the constructor and it initializes the data structure to hold the specified number of indexes.

  • Set Value (idx, val): This property sets the value at a given index idx to value val.

  • Snapshot(): This method takes no parameters and returns the Snap ID. Snap ID is the number of times that the snapshot function was called, less 11, as we start the count at 00. The first time this function is called, it saves a snapshot and returns 00. The nthn^{th} time it is called, after saving the snapshot, it returns n−1 ...