Longest Common Prefix · Interview Problem

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Leetcode

Easy

Strings

Arrays

Longest Common Prefix

Find the longest prefix shared by every string in an array.

Acceptance 89%

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Problem Statement

Problem

Given an array of strings, return the longest prefix that appears at the start of every string.

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

A prefix is a substring that starts at the beginning of a string.

Notes

Compare the strings character by character from left to right.
The answer must be common to all strings, not just some of them.

Input Format

An array of strings strs.
strs[i] contains lowercase or mixed-case text depending on the platform variant.

Output Format

Return a single string: the longest common prefix across all strings in strs.

Constraints

1 <= strs.length
Strings may be empty in some variants.
The answer length is at most the length of the shortest string.

Examples

Sample cases returned by the problem API.

Example 1

Input

strs = ["flower", "flow", "flight"]

Output

"fl"

Explanation

All three strings start with fl, but the next character differs.

Example 2

Input

strs = ["dog", "racecar", "car"]

Output

""

Explanation

There is no character sequence that appears at the start of every string.

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