- lintcode: (74) First Bad Version
The code base version is an integer start from 1 to n. One day, someone
committed a bad version in the code case, so it caused this version and the
following versions are all failed in the unit tests. Find the first bad
You can call
isBadVersionto help you determine which version is the first
bad one. The details interface can be found in the code’s annotation part.
Given n =
isBadVersion(3) -> false
isBadVersion(5) -> true
isBadVersion(4) -> true
Here we are 100% sure that the 4th version is the first bad version.
Please read the annotation in code area to get the correct way to call
isBadVersion in different language. For example, Java is
You should call isBadVersion as few as possible.
基础算法中 Binary Search 的 lower bound. 找出满足条件的下界即可。
lower bound 的实现，这里稍微注意下lb 初始化为 0，因为 n 从1开始。ub 和 lb 分别都在什么条件下更新就好了。另外这里并未考虑
n <= 0 的情况。