【刷题-LeetCode】154 Find Minimum in Rotated Sorted Array II

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.
• Would allow duplicates affect the run-time complexity? How and why?

解 三种情况

class Solution {
public:
    int findMin(vector<int>& nums) {
        if(nums.size() == 1)return nums[0];
        int l = 0, r = nums.size()-1, mid;
        if(nums[r] > nums[l])return nums[l];
        while(l < r){
            mid = (l+r)/2;
            if(nums[mid] > nums[r])l = mid+1;
            else if(nums[mid] < nums[r])r = mid;
            else r = r - 1;
        }
        return nums[l];
    }
};