【Leetcode】Same Tree

题目链接：https://leetcode.com/problems/same-tree/

题目：

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.

思路：

递归两颗树，因为如果两棵树结构相同，访问的结点顺序是一样的，所以结点值不相等，则两颗树不相同。

算法：

public boolean isSameTree(TreeNode p, TreeNode q) {
		if (p == null && q == null) {
			return true;
		}
		if (p == null || q == null) {
			return false;
		}
		if (p.val == q.val) {
			boolean f1 = isSameTree(p.left, q.left);
			boolean f2 = isSameTree(p.right, q.right);
			return f1 && f2;
		} else {
			return false;
		}

	}