LeetCode278. First Bad Version

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 will return whether version is bad. Implement a function to find the first bad version. You should minimize the number of calls to the API.

/* The isBadVersion API is defined in the parent class VersionControl.      boolean isBadVersion(int version); */public class Solution extends VersionControl {    public static final int MAX_INT = Integer.MAX_VALUE;;    public int firstBadVersion(int n) {        int result = MAX_INT;        int start = 1;        int end = n;        int mid = 0;        while (start <= end) {            mid = start + ((end-start) >>> 1);            boolean bad = isBadVersion(mid);            if (bad) {                //是坏版本，先记录下来，然后需要继续往前找第一个坏版本                result = Math.min(result, mid);                end = mid - 1;            } else {                //不是坏版本，需要继续往后找                start = mid + 1;            }        }        return result;    }}