問題提出:
給定一個二叉樹,找出其最大深度。二叉樹的深度爲根節點到最遠葉子節點的最長路徑上的節點數。
說明: 葉子節點是指沒有子節點的節點。node
解決思路:遞歸法求解。從根結點向下遍歷,每遍歷到子節點depth+1。spa
代碼實現( ̄▽ ̄):code
# Definition for a binary tree node. # class TreeNode: # def __init__(self, x): # self.val = x # self.left = None # self.right = None class Solution: def maxDepth(self, root: TreeNode) -> int: if root==None: return 0 count = self.getDepth(root,0) return count def getDepth(self,node,count): if node!=None: num1 = self.getDepth(node.left,count+1); num2 = self.getDepth(node.right,count+1); num = num1 if num1>num2 else num2 return num else: return count
時間和空間消耗:blog