leetcode100. same tree

递归判断两个二叉树的节点值是否相同,代码特别简单。

100. Same Tree

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:

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Input:     1         1
/ /
2 3 2 3

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

Output: true

Example 2:

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Input:     1         1
/
2 2

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

Output: false

Example 3:

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Input:     1         1
/ /
2 1 1 2

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

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