LeetCode——Same Tree（判断两棵树是否相同）

问题：

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.

 

分析：

考虑使用深度优先遍历的方法，同时遍历两棵树，遇到不等的就返回。

代码如下：

/**

 * Definition for binary tree

 * 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 p==q;

        }

        if(p.val != q.val){

            return false;

        }

        return isSameTree(p.left,q.left)&& isSameTree(p.right,q.right);

    }

}