Day 26 — Daily JavaScript Algorithm

Find the Longest Common Prefix

Welcome to Day 26 of our Daily JavaScript Algorithm series! Today, we’ll solve the Longest Common Prefix problem — a common question in string manipulation and coding interviews.

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Problem Statement

Given an array of strings strs, return the longest common prefix shared among all the strings. If there is no common prefix, return an empty string "".

Example 1:

• Input: strs = ["flower", "flow", "flight"]
• Output: "fl"

Example 2:

• Input: strs = ["dog", "racecar", "car"]
• Output: ""
• Explanation: No common prefix exists.

Example 3:

• Input: strs = ["interview", "integrate", "intelligent"]
• Output: "int"

Approach 1: Horizontal Scanning

We take the first string as a reference and compare it with all other strings, shortening the prefix until it matches all.

Algorithm Steps:

1. Take the first string as prefix.