# 154. Find Minimum in Rotated Sorted Array II

Suppose an array sorted in ascending order is rotated at some pivot unknown to you beforehand.

(i.e.,  `[0,1,2,4,5,6,7]` might become  `[4,5,6,7,0,1,2]`).

Find the minimum element.

The array may contain duplicates.

**Example 1:**

```
Input: [1,3,5]
Output: 1
```

**Example 2:**

```
Input: [2,2,2,0,1]
Output: 0
```

**Note:**

* This is a follow up problem to [Find Minimum in Rotated Sorted Array](https://leetcode.com/problems/find-minimum-in-rotated-sorted-array/description/).
* Would allow duplicates affect the run-time complexity? How and why?

```cpp
// Binary Search
int findMin(vector<int>& nums) { // time: O(logn); space: O(1)
    if (nums.empty()) return -1;
    int left = 0, right = nums.size() - 1;
    while (left < right) {
        if (nums[left] < nums[right]) { // no rotation in [left, right]
            break;
        }
        int mid = left + (right - left) / 2;
        if (nums[left] < nums[mid]) { // [left, mid] is sorted
            left = mid + 1;
        } else if (nums[left] > nums[mid]) { // [mid + 1, right] is sorted
            right = mid;
        } else {
            ++left;
        }
    }
    return nums[left];
}
```

{% content-ref url="153.-find-minimum-in-rotated-sorted-array" %}
[153.-find-minimum-in-rotated-sorted-array](https://jimmylin1991.gitbook.io/practice-of-algorithm-problems/binary-search/153.-find-minimum-in-rotated-sorted-array)
{% endcontent-ref %}