The First Stranger

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

Domain

Python

Difficulty

easy

Seniority

L3

Problem

A short string of single-character status codes arrives in the order records were processed. Return the first code that appears exactly once, or an empty string if every code repeats.

Summary

In a crowd, the unique ones stand out first.

Practice This Problem

Solve this Python problem with real code execution. DataDriven runs your Python code in a real environment and checks it automatically.