#1021
Remove Outermost Parentheses
newbie · 145 · lc easy +13 · verified · 86.9% accepted · 3,722 likes · top 98%
Description
A valid parentheses string s is primitive if it is non-empty and cannot be written as the concatenation of two non-empty valid parentheses strings.
Every valid parentheses string has a unique primitive decomposition s = P1 + P2 + ... + Pk.
Return s after stripping the outermost parentheses from each primitive part.
Example 1:
Input: s = "(()())(())"
Output: "()()()"
Explanation:
The input string is "(()())(())", with primitive decomposition "(()())" + "(())".
After removing outer parentheses of each part, this is "()()" + "()" = "()()()".
Example 2:
Input: s = "(()())(())(()(()))"
Output: "()()()()(())"
Explanation:
The input string is "(()())(())(()(()))", with primitive decomposition "(()())" + "(())" + "(()(()))".
After removing outer parentheses of each part, this is "()()" + "()" + "()(())" = "()()()()(())".
Example 3:
Input: s = "()()"
Output: ""
Explanation:
The input string is "()()", with primitive decomposition "()" + "()".
After removing outer parentheses of each part, this is "" + "" = "".
Code
1
2
3