Chapter2-Typescript.js

/**
 * Given a number n pairs of parentheses, generate all combinations of valid parentheses
Example 1:

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

 * @param {number} n: Number of given parentheses
 * @return {string[]} result: Array that contains all valid parentheses
 * @see https://leetcode.com/problems/generate-parentheses/
 *
 */
const generateParentheses = (n) => {
    const result = [];
    const solve = (chars, openParentheses, closedParentheses) => {
        if (openParentheses === n && closedParentheses === n) {
            result.push(chars);
            return;
        }
        if (openParentheses <= n) {
            solve(chars + '(', openParentheses + 1, closedParentheses);
        }
        if (closedParentheses < openParentheses) {
            solve(chars + ')', openParentheses, closedParentheses + 1);
        }
    };
    solve('', 0, 0);
    return result;
};
console.log(generateParentheses(3));