Package g0601_0700.s0655_print_binary_tree

Class Solution

java.lang.Object

g0601_0700.s0655_print_binary_tree.Solution

public class Solution
extends Object

655 - Print Binary Tree.

Medium

Given the root of a binary tree, construct a 0-indexed m x n string matrix res that represents a formatted layout of the tree. The formatted layout matrix should be constructed using the following rules:

• The height of the tree is height and the number of rows m should be equal to height + 1.
• The number of columns n should be equal to 2height+1 - 1.
• Place the root node in the middle of the top row (more formally, at location res[0][(n-1)/2]).
• For each node that has been placed in the matrix at position res[r][c], place its left child at res[r+1][c-2<sup>height-r-1</sup>] and its right child at res[r+1][c+2<sup>height-r-1</sup>].
• Continue this process until all the nodes in the tree have been placed.
• Any empty cells should contain the empty string "".

Return the constructed matrix res.

Example 1:

Input: root = [1,2]

Output: [[““,“1”,””], [“2”,““,””]]

Example 2:

Input: root = [1,2,3,null,4]

Output: [[““,””,““,“1”,””,““,””], [““,“2”,””,““,””,“3”,""], [““,””,“4”,““,””,““,””]]

Constraints:

• The number of nodes in the tree is in the range [1, 210].
• -99 <= Node.val <= 99
• The depth of the tree will be in the range [1, 10].

Constructor Summary

Constructors

Constructor	Description
Solution()

Method Summary

Modifier and Type	Method	Description
List<List<String>>	printTree(TreeNode root)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

Solution

public Solution()

Method Details

printTree

public List<List<String>> printTree(TreeNode root)