153. Find Minimum in Rotated Sorted Array

解題思路

要找斷裂處的右側值。又根據特性，斷裂處右側的數字都會比 index 0 來的小，所以可以用二分搜尋來縮小與排除。

程式碼

class Solution {
public:
    int findMin(vector<int>& nums) {
        int left = 0, right = nums.size() - 1, mid;
        if(nums.size() == 1 || nums[0] < nums[nums.size() - 1])
            return nums[0];

        while(left <= right)
        {
            mid = (left + right) / 2;
            if(nums[0] <= nums[mid])
                left = mid + 1;
            else
                right = mid - 1;
        }
        return nums[left];
    }
};