2019-11-02 12:07:41 +08:00
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# 28. 对称的二叉树
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2022-01-07 09:00:01 +00:00
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[NowCoder](https://www.nowcoder.com/practice/ff05d44dfdb04e1d83bdbdab320efbcb?tpId=13\&tqId=11211\&tPage=1\&rp=1\&ru=/ta/coding-interviews\&qru=/ta/coding-interviews/question-ranking\&from=cyc\_github)
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2019-11-02 12:07:41 +08:00
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## 题目描述
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2022-01-07 09:00:01 +00:00
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\
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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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boolean isSymmetrical(TreeNode pRoot) {
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if (pRoot == null)
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return true;
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return isSymmetrical(pRoot.left, pRoot.right);
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}
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boolean isSymmetrical(TreeNode t1, TreeNode t2) {
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if (t1 == null && t2 == null)
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return true;
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if (t1 == null || t2 == null)
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return false;
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if (t1.val != t2.val)
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return false;
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return isSymmetrical(t1.left, t2.right) && isSymmetrical(t1.right, t2.left);
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}
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```
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