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【LeetCode】81. Search in Rotated Sorted Array II

题目:

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.

 这题跟上一题一样,都是二分查找法,但是需要思考,对于时间复杂度,存在重复元素会有影响吗?可以考虑如[1,0,1,1,...,1]这样的数组,时间复杂度最坏会 变成O(N)。

class Solution {public:    int search(vector<int>& nums, int target)    {       int left = 0, right = nums.size()-1;       while(left <= right)       {           int middle = left + ((right-left)>>1);           if (nums[middle] == target) return true;           if (nums[middle] < nums[right])           {               if (nums[middle] < target && target <= nums[right])left = middle + 1;               else  right = middle - 1;           }           else if (nums[middle] > nums[right])           {               if (nums[left] <= target && target < nums[middle])right = middle - 1;               else left = middle + 1;           }           else  right--;       }       return false;    }};

 

【LeetCode】81. Search in Rotated Sorted Array II