Find Minimum in Rotated Sorted Array II
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.
class Solution {
public:
int findMin(vector<int>& nums, int b, int e){
int minVal = nums[b];
for(int i = b + 1; i <= e; i++){
minVal = min(minVal, nums[i]);
}
return minVal;
}
int findMin(vector<int>& nums) {
int mid;
int left = 0;
int right = nums.size() - 1;
while(left < right){
mid = left + (right - left) / 2;
if(nums[mid] == nums[right] && nums[mid] == nums[left]){
return findMin(nums, left, right);
}
if(nums[mid] == nums[left]){
if(nums[mid] < nums[right]){ // --/-
return findMin(nums, mid, right);
}
if(nums[mid] > nums[right]){ //--\ -
left = mid + 1;
continue;
}
}
if(nums[mid] == nums[right]){
if(nums[mid] < nums[left]){// \--
return findMin(nums, left, mid);
}
if(nums[mid] > nums[left]){// /-- -
right = mid - 1;
continue;
}
}
if(nums[mid] > nums[right]){ // 1、/\ 2、/
left = mid + 1;
}else{
//正好位于拐点 3、\/ 4、\ -
if(nums[mid] < nums[mid - 1]){
return nums[mid];
}
right = mid - 1;
}
}
return nums[left];
}
};