leetCode - Generate Parentheses

문제

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

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풀이

const generateParenthesis = function (n) {
    const result = [];

    function backtrack(left, right, parentheses) {
        if (left === n && right === n) {
            result.push(parentheses);
            return;
        }

        if (left < n) backtrack(left + 1, right, `${parentheses}(`);
        if ((left > right) && (right < n)) backtrack(left, right + 1, `${parentheses})`);
    }
    backtrack(0, 0, '');

    return result;
};