Problem

At Dropbox, file path suggestions may share a common starting segment. Given an array of strings, write a function that returns the longest common prefix shared by all strings.

If there is no common prefix, return an empty string "".

Formal Specification

• Input: A list of strings strs
• Output: A string representing the longest prefix common to every string in the list

Examples

Example 1

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

Explanation: All three strings start with "fl", but not all start with "flo".

Example 2

Input: strs = ["dog", "racecar", "car"]
Output: ""

Explanation: The strings do not share any starting characters.

Constraints

• 1 <= len(strs) <= 200
• 0 <= len(strs[i]) <= 200
• strs[i] consists of English letters only

Notes

A correct solution should compare prefixes efficiently and handle edge cases such as a single string, empty strings, or an immediate mismatch at the first character.