08. BalancedParentheses

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;

namespace E08_BalancedParentheses
{
    class BalancedParentheses
    {
        static void Main(string[] args)
        {
            // 75% - 2 Wrong Tests - 4, 8
            // https://judge.softuni.bg/Contests/Practice/Index/1447#7

            string input = Console.ReadLine();
            if (input.Length % 2 != 0 || input == "")
            {
                Console.WriteLine("NO");
            }
            else
            {
                int halfStringLength = input.Length / 2;
                string firstHalf = input.Substring(0, halfStringLength);
                string secondHalf = input.Substring(halfStringLength);
                Stack<char> first = new Stack<char>(firstHalf);
                Stack<char> second = new Stack<char>(secondHalf.Reverse());
                bool isValid = true;
                for (int i = 0; i < halfStringLength; i++)
                {
                    if ((first.Peek() == '(' && second.Peek() == ')')
                        || (first.Peek() == '[' && second.Peek() == ']')
                        || (first.Peek() == '{' && second.Peek() == '}'))
                    {
                        first.Pop();
                        second.Pop();
                    }
                    else
                    {
                        isValid = false;
                        break;
                    }
                }

                if (isValid)
                {
                    Console.WriteLine("YES");
                }
                else
                {
                    Console.WriteLine("NO");
                }
            }
        }
    }
}