DIY: First Bad Version

Solve the interview question "First Bad Version" in this lesson.

Problem statement

The latest version of a software product fails the quality check. Since each version is developed upon the previous one, all the versions created after a bad version are also considered bad. Suppose you have n versions with the following IDs:[1, 2, ..., n]. Your task is to find the first bad one, which is causing all the later ones to be bad.

Consider that you have the access to an API call, VersionControl::isBadVersion(), that returns true if the input is the ID of a bad version. You have to implement a solution with the minimum number of API calls.

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