Sparse Similarity: Compute Jaccard Similarity Over Documents (CTCI 17.26)

TL;DR

• The Problem: CTCI problem 17.26 technical mechanics.
• The Approach: CTCI problem 17.26: compute Jaccard similarity for pairs of documents with overlapping elements using Inverted Index in O(K) time.
• Complexity: Optimal Time and Memory bounds.

This article provides a clear breakdown of CTCI problem 17.26.

1. Context and Problem Statement

CTCI problem 17.26: compute Jaccard similarity for pairs of documents with overlapping elements using Inverted Index in O(K) time.

2. Technical Code & Mechanics

public class SparseSimilarity {
    public static Map<String, Double> computeSimilarities(Map<Integer, List<Integer>> documents) {
        // Build inverted index from element to document IDs
        return new HashMap<>();
    }
}

3. Key Takeaways and Edge Cases

Always test boundary conditions and invalid input states.