Generate Parentheses
Medium · Stack
You are given a single integer n. Build every valid string of length 2n that uses exactly n opening parentheses and n closing parentheses so that at no point in the string do the closing parentheses outnumber the opening ones read so far. Return all such well-formed combinations, in any order.
Examples
Input: n = 1
Output: ["()"]
Why: With one pair, the only balanced arrangement is ().Input: n = 2
Output: ["(())", "()()"]
Why: These are the only two ways to nest or sequence two pairs of parentheses without ever closing more than has been opened.Input: n = 3
Output: ["((()))", "(()())", "(())()", "()(())", "()()()"]
Why: All five balanced arrangements of three parenthesis pairs, listed here as an unordered set.Constraints
1 <= n <= 8
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This statement is written for CodeSpeek. The problem is part of the NeetCode 150 list; Watch NeetCode's explanation of Generate Parentheses. Reference solutions from the NeetCode repository (MIT) are used to verify our tests.