11.二叉查詢樹中搜索區間

給定一個二叉查詢樹和範圍[k1, k2]。按照升序返回給定範圍內的節點值。

樣例

樣例 1:

輸入：{5},6,10
輸出：[]
        5
它將被序列化為 {5}
沒有數字介於6和10之間

樣例 2:

輸入：{20,8,22,4,12},10,22
輸出：[12,20,22]
解釋：
        20
       /  \
      8   22
     / \
    4   12
它將被序列化為 {20,8,22,4,12}
[12,20,22]介於10和22之間

中序遍歷,遞迴

"""
Definition of TreeNode:
class TreeNode:
    def __init__(self, val):
        self.val = val
        self.left, self.right = None, None
"""

class Solution:
    """
    @param root: param root: The root of the binary search tree
    @param k1: An integer
    @param k2: An integer
    @return: 
 
return: Return all keys that k1<=key<=k2 in ascending order
    """
    def searchRange(self, root, k1, k2):
        # write your code here
        #二叉查詢樹，中序遍歷
        if not root: return []
        
        results = []
        self.midTravel(root, results,k1,k2)
        
        return results
    
    def midTravel(self, root,results, k1, k2):
        #遞迴出口
        
 
if not root: return 
        
        self.midTravel(root.left,results, k1, k2)
        if (root.val >= k1) and (root.val <=  k2):
            results.append(root.val)
        
        self.midTravel(root.right,results,k1,k2)