Symmetric Tree，对称树

问题描述：

Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center).

For example, this binary tree [1,2,2,3,4,4,3] is symmetric:

But the following [1,2,2,null,3,null,3] is not:

算法分析：和same tree比较像，都可以用递归方法来解决。

public class SymmeticTree

{

	public boolean isSymmetric(TreeNode root)

	{

		if (root == null)

		{

			return true;

		}

		return isSymmetric(root.left, root.right);

	}

	public boolean isSymmetric(TreeNode left, TreeNode right)

	{

		if (left == null && right == null)

		{

			return true;

		}

		else if ((left == null && right != null)

				|| (right == null && left != null) || (left.val != right.val))

		{

			return false;

		}

		else

		{

			return isSymmetric(left.left, right.right)

					&& isSymmetric(left.right, right.left);

		}

	}

}

巴特西

Symmetric Tree，对称树

最新文章

热门文章