LeetCode Easy Same Tree

最新推荐文章于 2019-01-21 10:11:21 发布

nuttee

最新推荐文章于 2019-01-21 10:11:21 发布

阅读量151

点赞数

分类专栏： LeetCode

本文链接：https://blog.youkuaiyun.com/lrwwll/article/details/86410726

版权

LeetCode 专栏收录该内容

31 篇文章

订阅专栏

本文介绍了一种检查两棵二叉树是否完全相同的方法，包括结构和节点值的比较。通过递归函数实现，判断两棵树是否在结构上一致且所有对应节点的值相等。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

Given two binary trees, write a function to check if they are the same or not.

Two binary trees are considered the same if they are structurally identical and the nodes have the same value.

Example 1

Input:     1         1
          / \       / \
         2   3     2   3

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

Output: true

Exampel 2

Input:     1         1
          /           \
         2             2

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

Output: false

Example 3

Input:     1         1
          / \       / \
         2   1     1   2

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

Output: false

Solution1

public class TreeNode {
    int val;
    TreeNode left;
    TreeNode right;
    TreeNode(int x) { val = x; }
}

public class Solution1 {
    /**
     * Recursive
     * @param p the first tree
     * @param q the second tree
     * @return boolean true if the two tree are the totally same
     */
    public boolean isSameTree(TreeNode p, TreeNode q) {
        if (p == null && q == null) return true;
        if ((p == null) || (q == null)) return false;
        return p.val == q.val && isSameTree(p.left, q.left) && isSameTree(p.right, q.right);
    }
}