What the Card Remembers

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

Domain

Python

Difficulty

medium

Seniority

mid

Problem

A card-authorization service records temporary holds as `[start, end]` minute offsets, and a single card can accumulate many holds that pile onto each other over a busy day. For each card, collapse the holds that overlap or touch into the continuous windows the money was actually held, earliest first.

Summary

A hold on your money is never a single moment. Rebuild the windows it actually lived in.

Practice This Problem

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