100. 相同的树

原题

https://leetcode.cn/problems/same-tree/description/

思路

递归

复杂度

时间：O(n)
空间：O(n)

Python代码

# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, val=0, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right
class Solution:
    def isSameTree(self, p: Optional[TreeNode], q: Optional[TreeNode]) -> bool:
        if not p and not q:
            return True 
        if not p or not q:
            return False
        if p.val != q.val:
            return False 
        return self.isSameTree(p.left, q.left) and self.isSameTree(p.right, q.right)

Go代码

/**
 * Definition for a binary tree node.
 * type TreeNode struct {
 *     Val int
 *     Left *TreeNode
 *     Right *TreeNode
 * }
 */
func isSameTree(p *TreeNode, q *TreeNode) bool {
	if p == nil && q == nil {
		return true
	}
	if p == nil || q == nil {
		return false
	}
	if p.Val != q.Val {
		return false
	}
	return isSameTree(p.Left, q.Left) && isSameTree(p.Right, q.Right)
}