[Dichotomy] leetcode154: Find the minimum rotation sorted array Ⅱ (hard)

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Title:

Solution:

class Solution {
public:
    //解法1：STL算法
    int findMin_1(vector<int>& nums) {
        return *min_element(nums.begin(),nums.end());
    }
    
    //解法2：二分法
    //和 I 的做法类似, 都是二分法, 每次进入无序的那部分找出最小值，但是由于有重复值的情况, 需要加入 mid 元素等于 right 元素的情况，此时应该将 right 减 1 防止重复数字是最小元素
    int findMin_2(vector<int>& nums)
    {
        int left = 0, right = nums.size() - 1;
        while (left < right) {
            int mid = (left + right) / 2;
            if (nums[mid] > nums[right]) left = mid + 1;
            else if (nums[mid] < nums[right]) right = mid;
            else right = right - 1;
        }
        return nums[left];
    }
};