Backtracking Solution For LeetCode 22 (Generate Parenthesis)

genParenthesis.js

function generateParenthesis(n) {
    result = new Array();
    
    const backtrack = (op, cp, path = "", stack = new Array()) => {
        if (op < 0 || cp < 0) {
            return;
        }

        if (stack.length > 1 && stack.at(-1) === ")" && stack.at(-2) === "(") {
            stack = stack.slice(0, stack.length - 2);
        }

        if (op === 0 && cp === 0 && stack.length === 0) {
            result.push(path);
            return;
        }

        if (op === cp === 0 && stack.length !== 0) {
            return;
        }

        if (path.length === 0) {
            return backtrack(op - 1, cp, path + "(", [...stack, "("]);
        }

        backtrack(op - 1, cp, path + "(", [...stack, "("])
        backtrack(op, cp - 1, path + ")", [...stack, ")"])
    };

    backtrack(n, n);
    return result
}