LeetCode-081. Search in Rotated Sorted Array II

1. 题目

Search in Rotated Sorted Array II

在旋转有序数组中查找特定值
数组中有重复的数，查找特定值，若存在，返回true，若不存在，返回false
如[10,12,12,1,2,6,8,10] 10 返回true
[10,12,12,1,2,6,8,10] 0 返回false

2. 分析

类似于 Search in Rotated Sorted Array
但注意不是返回下标而是 true or false

数组中存在重复的数，则当nums[start]==nums[mid]
无法确定数组的递增序列，需要进一步查找

3. 代码

class Solution {
public:
    bool search(vector<int>& nums, int target) {
        const int len = nums.size();
        if(len <= 0)
            return 0;

        int left = 0;
        int right = len - 1;
        while(left <= right)
        {
            int mid = left + ((right - left) >> 1);
            if(target == nums[mid])
                return 1;

            if(nums[left] < nums[mid])
            {
                if(nums[left] <= target && target < nums[mid])
                    right = mid - 1;
                else
                    left = mid + 1;
            }
            else if(nums[left] > nums[mid])
            {
                if(nums[mid] < target && target <= nums[right])
                    left = mid + 1;
                else
                    right = mid - 1;
            }
            else
                ++left;
        }

        return 0;
    }
};

完整源代码放于github