leetcode278

/* The isBadVersion API is defined in the parent class VersionControl.
      bool IsBadVersion(int version); */

public class Solution : VersionControl {
    public int FirstBadVersion(int n) {
        var start = ;
            var end = n;
            while (start < end)
            {
                var mid = start + (end - start) / ;
                if (!IsBadVersion(mid))
                {
                    start = mid + ;
                }
                else
                {
                    end = mid;
                }
            }
            return start;
    }
}

https://leetcode.com/problems/first-bad-version/#/description