leetcode 81 :Search in Rotated Sorted Array II

Follow up for "Search in Rotated Sorted Array":
What if duplicates are allowed?

Would this affect the run-time complexity? How and why?

Write a function to determine if a given target is in the array.

分析：参考https://github.com/soulmachine/leetcode
允许重复元素，如果A[m]>=A[l], 那么[l,m] 为递增序列的假设就不能成立了，比
如[1,3,1,1,1]。
如果A[m]>=A[l] 不能确定递增，那就把它拆分成两个条件：
• 若A[m]>A[l]，则区间[l,m] 一定递增
• 若A[m]==A[l] 确定不了，那就l++，往下看一步即可。