problem606

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606. Construct String from Binary Tree (Easy)

Given the root of a binary tree, construct a string consists of parenthesis and integers from a binary tree with the preorder traversing way, and return it.

Omit all the empty parenthesis pairs that do not affect the one-to-one mapping relationship between the string and the original binary tree.

 

Example 1:

Input: root = [1,2,3,4]
Output: "1(2(4))(3)"
Explanation: Originallay it needs to be "1(2(4)())(3()())", but you need to omit all the unnecessary empty parenthesis pairs. And it will be "1(2(4))(3)"

Example 2:

Input: root = [1,2,3,null,4]
Output: "1(2()(4))(3)"
Explanation: Almost the same as the first example, except we cannot omit the first parenthesis pair to break the one-to-one mapping relationship between the input and the output.

 

Constraints:

• The number of nodes in the tree is in the range [1, 104].
• -1000 <= Node.val <= 1000

Related Topics

[Tree] [Depth-First Search] [String] [Binary Tree]

Similar Questions

1. Construct Binary Tree from String (Medium)
2. Find Duplicate Subtrees (Medium)

Documentation

Index

• type TreeNode

Types

type TreeNode

type TreeNode = kit.TreeNode

TreeNode - Definition for a binary tree node.