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.

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