[leetcode]Symmetric Tree
2014-07-31 19:53
369 查看
Symmetric Tree
Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center).
For example, this binary tree is symmetric:
But the following is not:
Note:
Bonus points if you could solve it both recursively and iteratively.
算法思路：
思路：递归。镜像判断。
代码如下：
Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center).
For example, this binary tree is symmetric:
1 / \ 2 2 / \ / \ 3 4 4 3
But the following is not:
1 / \ 2 2 \ \ 3 3
Note:
Bonus points if you could solve it both recursively and iteratively.
算法思路：
思路：递归。镜像判断。
代码如下：
public class Solution {
public boolean isSymmetric(TreeNode root) {
if(root == null || (root.left == null && root.right == null)) return true;
return isSym(root.left, root.right);
}
public boolean isSym(TreeNode left,TreeNode right){
if(left == null && right == null) return true;
if((left == null && right != null) || (left != null && right == null) || right.val != left.val)
return false;
return isSym(left.left, right.right) && isSym(left.right, right.left);
}
}
内容来自用户分享和网络整理，不保证内容的准确性，如有侵权内容，可联系管理员处理 
相关文章推荐
- LeetCode 101. Symmetric Tree（对称的树）
- LeetCode--No.101--Symmetric Tree
- LeetCode || Symmetric Tree
- LeetCode101——Symmetric Tree
- (leetcode)Symmetric Tree
- leetcode 101: Symmetric Tree
- leetcode：Symmetric Tree 【Java】
- 【leetcode】Symmetric Tree
- [leetcode] Symmetric Tree－－二叉树遍历的应用
- leetcode -- Symmetric Tree
- [LeetCode] Symmetric Tree
- leetcode 101: Symmetric Tree
- leetcode：Symmetric Tree
- LeetCode 101 Symmetric Tree（对称树）（*）
- LeetCode 101:Symmetric Tree
- 【leetcode】Symmetric Tree
- LeetCode 101:Symmetric Tree
- LeetCode:Symmetric Tree
- Symmetric Tree [LeetCode]
- LeetCode之Symmetric Tree