Practice First Bad Version

Read the task, work through the examples, and check your approach against the constraints. Use the original LeetCode task for coding and submissions.

Easy#278

LeetCode Problem

First Bad Version

Binary Search Interactive

Problem Statement

You are a product manager and currently leading a team to develop a new product. Unfortunately, the latest version of your product fails the quality check. Since each version is developed based on the previous version, all the versions after a bad version are also bad. Suppose you have n versions [1, 2, ..., n] and you want to find out the first bad one, which causes all the following ones to be bad. You are given an API bool isBadVersion(version) which returns whether version is bad. Implement a function to find the first bad version. You should minimize the number of calls to the API.

Source: First Bad Version on LeetCode. Use the original task for its coding environment and submissions.

Examples

# Example 1

Input

n = 5, bad = 4

Output

# Example 2

Input

n = 1, bad = 1

Output

Constraints

1 <= bad <= n <= 2^31 - 1

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