技術標籤：力扣leetcode演算法python

陣列中的第K個最大值

 class Solution:
    def findKthLargest(self, nums: List[int], k: int) -> int:
        n=len(nums)
        target=n-k 
        left=0
        right=n-1

        while True:
            index=self.partition(nums,left,right)
            if index==target:
                return
 
 nums[index]

            elif index<target:
                left=index+1

            else:
                right=index-1
                
    def partition(self,nums,left,right):
        pivot=nums[left] #選定一個分割點
        i=left  

        for j in range(left+1,right+1):
            if nums[j]<
 
pivot: 
                i+=1
                nums[j],nums[i]=nums[i],nums[j]

        nums[left],nums[i]=nums[i],nums[left]

        return i

存在重複元素

```python
class Solution:
    def containsDuplicate(self, nums: List[int]) -> bool:
        return len(nums)!=len(set(nums))

二叉搜尋樹中的第K小的元素

class Solution
 
:
    def kthSmallest(self, root: TreeNode, k: int) -> int:
        def inorder(r):
            return inorder(r.left)+[r.val]+inorder(r.right) if r else []
		return inorder(root)[k-1]