leetcode 100. Same Tree

Given two binary trees, write a function to check if they are equal or not.

Two binary trees are considered equal if they are structurally identical and the nodes have the same value.

简单的递归。扩展版题目:leetcode 572

C++版:

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {
public:
    bool isSameTree(TreeNode* p, TreeNode* q) {
        if(p==nullptr&&q==nullptr){
            return true;
        }
        else if(p==nullptr||q==nullptr){
            return false;
        }
        if(p->val==q->val){
            return isSameTree(p->left,q->left)&&isSameTree(p->right,q->right);
        }
        return false;
    }
};

 python版:

# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None

class Solution:
    def isSameTree(self, p: TreeNode, q: TreeNode) -> bool:
        if (not p) and (not q):
            return True
        elif (not p) or (not q):
            return False
        else:
            if p.val==q.val:
                return self.isSameTree(p.left,q.left) and self.isSameTree(p.right,q.right)
            else:
                return False