# 26. 树的子结构

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## 题目描述

<div align="center"> <img src="https://cs-notes-1256109796.cos.ap-guangzhou.myqcloud.com/84a5b15a-86c5-4d8e-9439-d9fd5a4699a1.jpg" width="450"/> </div><br>

## 解题思路

```java
public boolean HasSubtree(TreeNode root1, TreeNode root2) {
    if (root1 == null || root2 == null)
        return false;
    return isSubtreeWithRoot(root1, root2) || HasSubtree(root1.left, root2) || HasSubtree(root1.right, root2);
}

private boolean isSubtreeWithRoot(TreeNode root1, TreeNode root2) {
    if (root2 == null)
        return true;
    if (root1 == null)
        return false;
    if (root1.val != root2.val)
        return false;
    return isSubtreeWithRoot(root1.left, root2.left) && isSubtreeWithRoot(root1.right, root2.right);
}
```






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