給定兩個二叉樹，編寫一個函式來檢驗它們是否相同。

如果兩個樹在結構上相同，並且節點具有相同的值，則認為它們是相同的。

示例 1:

輸入:       1         1
          / \       / \
         2   3     2   3

        [1,2,3],   [1,2,3]

輸出: true

示例 2:

輸入:      1          1
          /           \
         2             2

        [1,2],     [1,null,2]

輸出: false

示例 3:

輸入:       1         1
          / \       / \
         2   1     1   2

        [1,2,1],   [1,1,2]

輸出: false

C

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

python

# 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, q):
        """
        :type p: TreeNode
        :type q: TreeNode
        :rtype: bool
        """
        if None==p or None==q:
            if p==q:
                return True
            else:
                return False
        return p.val==q.val and self.isSameTree(p.left,q.left) and self.isSameTree(p.right,q.right)