Leetcode 278. First Bad Version

文章作者：Tyan
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1. Description

2. Solution

解析：问题变为给定有序数组[1, 2, 2]，找出第一个2的问题，最容易想到的就是二分查找。

class Solution:
    def firstBadVersion(self, n):
        left = 1
        right = n
        while left <= right:
            mid = (left + right) // 2
            if isBadVersion(mid):
                if mid == 1 or not isBadVersion(mid - 1):
                    return mid
                right = mid - 1
            else:
                left = mid + 1

Reference

1. https://leetcode.com/problems/first-bad-version/