Java [Leetcode 100]Same Tree

题目描述：

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.

解题思路：

递归调用比较左子树和右子树以及该节点。

代码描述：

/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */
public class Solution {
    public boolean isSameTree(TreeNode p, TreeNode q) {
    	if( p == null && q == null)
    		return true;
    	else if(p == null || q == null)
    		return false;
    	else
    		return p.val == q.val && isSameTree(p.left, q.left) && isSameTree(p.right, q.right);
    }
}