【LeetCode 153: Find Minimum in Rotated Sorted Array】

查找旋轉數組的最小值

Description:

Suppose a sorted array 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.
You may assume no duplicate exists in the array.

參考代碼：

class Solution {
public:
    int findMin(vector<int>& nums) 
    {
        int nRet = 0;
        if(!nums.empty())
        {
            int mid;
            int left = 0;
            int right = nums.size()-1;
            while(left < right)
            {
                mid = (left + right)/2;
                // 最小值在左半部分
                if(nums[mid] < nums[right])
                {
                    right = mid;
                }
                // 最小值在右半部分
                else if(nums[mid] > nums[right])
                {
                    left = mid + 1;
                }
            }
            nRet = nums[left];
        }
        return nRet;
    }
};

小結：

1：充分使用有序數組的信息；
2：學會類似二分查找的思想；