[JavaScript] 프로그래머스 괄호변환 LEVEL2

문제출처

const checkRight = (u) => {
    let stack = [];
    for (let i=0; i<u.length; i++) {
        if (u[i] === '(') stack.push('(');
        else {
            if (stack.length === 0) return false;
            stack.pop();
        }
    }
    return true;
};

const divide = (str) => {
    let stack = [str[0]];
    
    for (let i=1; i<str.length; i++) {
        if (stack[0] === str[i]) stack.push(str[i]);
        else {
            stack.pop();
        }
        
        if (stack.length === 0) {
            const s = str.join('');
            return [s.substring(0, i+1), s.substring(i+1)];
        }
        
    }
    return [str.join(''), ''];
};

const change = (u) => {
    let str = '';
    for (let i=1; i<u.length-1; i++) {
        if (u[i] === '(') str += ')';
        else str += '(';
    }
    return str;
};

function solution(p) {
    let answer = '';
    let str = p.split('');
    
    while (answer.length < p.length) {
        const [u, v] = divide(str);
        const rightU = checkRight(u);

        if (rightU) answer += u;
        else answer += '(' + solution(v) + ')' + change(u);
        
        str = str.slice(u.length);
    }
    
    return answer;
}