Jaccard Business Similarity

Problem

Given two business names provided as strings s1 and s2, determine their Jaccard similarity index. This index equals the number of distinct words the two names share divided by the total distinct words present across both names together. Round the result to two decimal places. When both strings are blank, return 1.0.

Constraints

• Each string contains words delimited by a single space.
• Business name comparison respects casing (case-sensitive).

Examples

Example 1:

Input:  s1 = "Roof Repair", s2 = "Larry's Roof Repair"
Output: 0.67

Explanation:

• Distinct words in s1: ["Roof", "Repair"]
• Distinct words in s2: ["Larry's", "Roof", "Repair"]
• Intersection: ["Roof", "Repair"] (2 words)
• Union: ["Larry's", "Roof", "Repair"] (3 words)
• Jaccard index = 2 / 3 ≈ 0.666..., which rounds to 0.67.

Example 2:

Input:  s1 = "Plumbing Service", s2 = "Plumbing Service"
Output: 1.0

Example 3:

Input:  s1 = "Coffee Shop", s2 = "Auto Repair"
Output: 0.0

Explanation: The two strings have zero words in common, giving an intersection size of 0 and a similarity of 0.0.