题目:
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.
思路:
用二分法。
程序:
class Solution {
public:
int findMin(vector<int>& nums) {
if(nums.empty())
return 0;
if(nums.size() == 1)
return nums[0];
int n = nums.size();
int low = 0;
int high = n-1;
while(low < high && nums[low] >= nums[high])
{
int mid = low + (high-low)/2;
if(nums[mid] < nums[low])
high = mid;
else if(nums[mid] == nums[low])
low ++;
else
low = mid+1;
}
return nums[low];
}
};