Package g0201_0300.s0278_first_bad_version

Class VersionControl

java.lang.Object
g0201_0300.s0278_first_bad_version.VersionControl
Direct Known Subclasses:
Solution
public class VersionControl extends java.lang.Object
278 - First Bad Version.

Easy

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.

Example 1:

Input: n = 5, bad = 4

Output: 4

Explanation:

 call isBadVersion(3) -> false
 call isBadVersion(5) -> true
 call isBadVersion(4) -> true
 Then 4 is the first bad version.

Example 2:

Input: n = 1, bad = 1

Output: 1

Constraints:

  • 1 <= bad <= n <= 231 - 1

  • Constructor Summary

    Constructors
    Constructor
    Description
    VersionControl(int bad)
     

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    isBadVersion(int version)
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • VersionControl

      public VersionControl(int bad)

  • Method Details

    • isBadVersion

      public boolean isBadVersion(int version)