using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        ValidParantheses validParantheses = new ValidParantheses();

        string s1 = "{([])}";

        Console.WriteLine(s1);

        Console.WriteLine(validParantheses.InString(s1));

        Console.WriteLine("----------------------------");

        string s2 = "(){}[]";

        Console.WriteLine(s2);

        Console.WriteLine(validParantheses.InString(s2));

        Console.WriteLine("----------------------------");

        string s3 = "{([])}[";

        Console.WriteLine(s3);

        Console.WriteLine(validParantheses.InString(s3));

        Console.WriteLine("----------------------------");

        string s5 = "{([])})";

        Console.WriteLine(s5);

        Console.WriteLine(validParantheses.InString(s5));

        Console.WriteLine("----------------------------");

        string s4 = "[(])";

        Console.WriteLine(s4);

        Console.WriteLine(validParantheses.InString(s4));

        Console.WriteLine("----------------------------");

    }

}

​

public class ValidParantheses

{

    private Dictionary<char,char> _paranthesesDictionary;

    public ValidParantheses()

    {

        _paranthesesDictionary = GetParanthesesDictionary();

    }

    public bool InString(string line)

    {

        Stack<char> stack = new Stack<char>();

        foreach(char c in line)

        {

            if(c == '{' || c == '(' || c == '[')

                stack.Push(c);

            else

            {

                if(stack.Count==0) return false;

                if(stack.Peek() == _paranthesesDictionary[c])

                    stack.Pop();

                else

                    return false;

            }

        }

        if(stack.Count == 0) return true;

        else return false;

    }

    private Dictionary<char,char> GetParanthesesDictionary()

    {

        Dictionary<char,char> dictionary = new Dictionary<char,char>();

        dictionary.Add('}','{');

        dictionary.Add(')','(');

        dictionary.Add(']','[');

        return dictionary;

    }

}