Leetcode--Find Minimum in Rotated Sorted Array

Find Minimum in Rotated Sorted Array

原题：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.
此题第一想法就是：将第一个元素赋值给min，然后追个扫描每个元素，若有比该值小的元素，则更新min。最后返回min。时间复杂度为O(n),代码如下：

class Solution {
public:
    int findMin(vector<int> &num) {
        int min=0;
        min = num[0];
        for(int i=0;i<num.size();++i)
        {
            if( min < num[i])
                continue;
            else
                min = num[i];
        }
        return min;
    }
};

还有一种做法是将原有数组进行排序，但是会改变原有数组，时间复杂度为O(n*logn).代码如下：

class Solution {
public:
    int findMin(vector<int> &num) {
        sort(num.begin(),num.end());
        return num[0];
    }
};