2019-11-02 12:07:41 +08:00
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# 26. 树的子结构
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[NowCoder](https://www.nowcoder.com/practice/6e196c44c7004d15b1610b9afca8bd88?tpId=13&tqId=11170&tPage=1&rp=1&ru=/ta/coding-interviews&qru=/ta/coding-interviews/question-ranking&from=cyc_github)
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## 题目描述
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2019-11-02 14:39:13 +08:00
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<div align="center"> <img src="https://cs-notes-1256109796.cos.ap-guangzhou.myqcloud.com/84a5b15a-86c5-4d8e-9439-d9fd5a4699a1.jpg" width="450"/> </div><br>
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2019-11-02 12:07:41 +08:00
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## 解题思路
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```java
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public boolean HasSubtree(TreeNode root1, TreeNode root2) {
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if (root1 == null || root2 == null)
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return false;
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return isSubtreeWithRoot(root1, root2) || HasSubtree(root1.left, root2) || HasSubtree(root1.right, root2);
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}
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private boolean isSubtreeWithRoot(TreeNode root1, TreeNode root2) {
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if (root2 == null)
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return true;
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if (root1 == null)
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return false;
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if (root1.val != root2.val)
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return false;
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return isSubtreeWithRoot(root1.left, root2.left) && isSubtreeWithRoot(root1.right, root2.right);
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}
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```
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2019-11-02 14:39:13 +08:00
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<div align="center"><img width="320px" src="https://cs-notes-1256109796.cos.ap-guangzhou.myqcloud.com/githubio/公众号二维码-1.png"></img></div>
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