[Leetcode100]相同的树

给定两个二叉树，编写一个函数来检验它们是否相同。

如果两个树在结构上相同，并且节点具有相同的值，则认为它们是相同的。

二话不说上来就是递归。

python:

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

class Solution(object):
    def isSameTree(self, p, q):
        """
        :type p: TreeNode
        :type q: TreeNode
        :rtype: bool
        """
        if p != None and q != None:
            if p.val == q.val:
                return self.isSameTree(p.left,q.left) & self.isSameTree(p.right,q.right)
            else:
                return False
        if p == None and q != None:
            return False
        if p != None and q == None:
            return False
        if p == None and q == None:
            return True

C++: 

/**
 * 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 != NULL && q != NULL){
            if(p->val == q->val) return isSameTree(p->left,q->left) & isSameTree(p->right,q->right);
            else return false;
        }
        if(p == NULL && q != NULL) return false;
        if(p != NULL && q == NULL) return false;
        if(p == NULL && q == NULL) return true;
    }
};