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22. Generate Parentheses
Medium
Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses.
Example 1:
Input: n = 3
Output: [”((()))”,”(()())”,”(())()”,”()(())”,”()()()”]
Example 2:
Input: n = 1
Output: [”()”]
Constraints:
1 <= n <= 8
Solution
function generateParenthesis(n: number): string[] {
const sb: string[] = []
const ans: string[] = []
return generate(sb, ans, n, n)
}
function generate(sb: string[], str: string[], open: number, close: number): string[] {
if (open === 0 && close === 0) {
str.push(sb.join(''))
return str
}
if (open > 0) {
sb.push('(')
generate(sb, str, open - 1, close)
sb.pop()
}
if (close > 0 && open < close) {
sb.push(')')
generate(sb, str, open, close - 1)
sb.pop()
}
return str
}
export { generateParenthesis }