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

namespace Simple
{
    class Program
    {

        #region valid
        static string validString = "" +
            "int a = 0;" +
            "int b = 10;" +
            "while(a+b<100){" +
            "a++;" +
            "str s = \"asd\"" +
            "};";
        #endregion
        #region not valid
        static string notValidString = "" +
            "int a = {0;" +
            "(int b = 10;" +
            "while}(a+b<100){" +
            "a++;)" +
            "};";
        #endregion
        static void Main(string[] args)
        {
            List<string> strings = new List<string>() { validString, notValidString, "{[(])}" };
            foreach (var str in strings)
            {
                Console.WriteLine($"string is { CheckValid(str)}");
            }

        }
        public static readonly char[] symbs = { '{', '[','(','\'','"','}',']',')'};
        private static bool CheckValid(string str){
            if (str == null)
                throw new ArgumentException("String is null");
            char[] lex = str.Where(c=> symbs.Contains(c)).ToArray();
            Stack<char> opens = new Stack<char>();
            foreach(var c in lex){
                switch(c){
                    case '{':
                    case '[':
                    case '(':
                        opens.Push(c);
                        continue;
                    case '"':
                    case '\'':
                        if (opens.Peek() != c){
                            opens.Push(c);
                            continue;}
                        break;}
                //Закрывающие
                switch(c){
                    case '}':
                        if (opens.Peek() == '{')
                            opens.Pop();
                        break;
                    case ']':
                        if (opens.Peek() == '[')
                            opens.Pop();
                        break;
                    case ')':
                        if (opens.Peek() == '(')
                            opens.Pop();
                        break;
                    case '\'':
                        if (opens.Peek() == '\'')
                            opens.Pop();
                        break;

                    case '"':
                        if (opens.Peek() == '"')
                            opens.Pop();
                        break;}}
            return !opens.Any();
        }
    }
}