Where They Part

A hard Python interview practice problem on DataDriven. Write and execute real python code with instant feedback.

Domain

Python

Difficulty

hard

Seniority

L4

Problem

You are given `patterns`, a batch of object-storage key globs where `?` matches any single character. Return the longest leading run of positions where the patterns can all agree, resolved to its characters: a position holds when every non-`?` character there is identical, and the run ends the instant two concrete characters clash or any pattern runs out. Return an empty string when `patterns` is empty.

Summary

They all start the same way. How far?

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