Neil coding之路

Have a nice day

0%

Javascript(leetcode#22) Generate Parentheses

發表於 更新於 分類於 ， Disqus：

Difficult:Medium

題目

Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses.

翻譯

給定 n 對括號，編寫一個函數來生成格式正確的括號的所有組合。

範例

Example 1

1
2
Input: n = 3
Output: ["((()))","(()())","(())()","()(())","()()()"]

Example 2

1
2
Input: n = 1
Output: ["()"]

解題思路

Solution

Code 1 :

1
2
3
4
5
6
7
8
9
10
11
var generateParenthesis = function (n) {
    let res = [];
    function helper(s, l, r) {
      if (l === 0 && r === 0) res.push(s);
      if (l > 0) helper(s + "(", l - 1, r);
      if (r > l) helper(s + ")", l, r - 1);
      return res;
    }
    return helper("", n, n);
    
  };