Find Minimum in Rotated Sorted Array问题及解法

问题描述：

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.

You may assume no duplicate exists in the array.
问题分析：
一类典型的二分查找法。

过程详见代码：

class Solution {
public:
int findMin(vector<int>& nums) {
int a = 0, b = nums.size() - 1;

while (a < b) {
if (nums[a] < nums[b])
return nums[a];

int mid = (a + b) / 2;
if (nums[mid] > nums[b])
a = mid + 1;
else
b = mid;
}

return nums[a];
}
};