LeetCode100. Same Tree（二叉树）

Same Tree Category Difficulty Likes Dislikes algorithms Easy (49.97%) 1116 34 Tags Companies 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 Example 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

题意

判断两棵二叉树是否相等

思路

递归

代码

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 if (p != null && q == null) { return false; } else if (isSameTree(p.left, q.left) && p.val == q.val && isSameTree(p.right, q.right)) { return true; } else { return false; } } }