leetcode_c++: Find Minimum in Rotated Sorted Array II(154)

题目

Follow up for “Find Minimum in Rotated Sorted Array”:

What if duplicates are allowed?

Would this affect the run-time complexity? How and why?

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.

The array may contain duplicates.

算法

O（logn）

最坏O（N）：全部都是一样的

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

int mid, ans=nums[0];
while(left<=right){
mid=(left+right)/2;
if(nums[left]<nums[right]){
ans=min(ans,nums[left]);
left=mid+1;
}else if(nums[right]>nums[left]){
ans=min(ans,nums[mid]);
right=mid;
}else{
ans=min(ans,nums[left]);
++left;
}
}
return ans;
}
};