- Difficulty: Medium
- Tags: LeetCode, Medium, Tree, Depth-First Search, String, Binary Tree, leetcode-536, O(n), O(h), 🔒, Stack
Problem
You need to construct a binary tree from a string consisting of parenthesis and integers.
The whole input represents a binary tree. It contains an integer followed by zero, one or two pairs of parenthesis. The integer represents the root's value and a pair of parenthesis contains a child binary tree with the same structure.
You always start to construct the left child node of the parent first if it exists.
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Example 1:
Input: s = "4(2(3)(1))(6(5))" Output: [4,2,6,3,1,5]
Example 2:
Input: s = "4(2(3)(1))(6(5)(7))" Output: [4,2,6,3,1,5,7]
Example 3:
Input: s = "-4(2(3)(1))(6(5)(7))" Output: [-4,2,6,3,1,5,7]
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Constraints:
0 <= s.length <= 3 * 104
s
consists of digits,'('
,')'
, and'-'
only.