using System; using System.Collections.Generic;

namespace Program { public class ParanthesisMatch { private readonly Dictionary<char, char> _matchingParanthesisCollection = new Dictionary<char, char> { { ')', '('}, { '}', '{'}, { ']', '['} };

    public bool IsMatched(String expression)
    {
        Stack<char> characterStack = new Stack<char>();
        char c;

        for (int i = 0; i < expression.Length; i++)
        {
            c = expression[i];

            if (c == '(' || c == '{' || c == '[')
                characterStack.Push(c);
            else if (c == ')' || c == '}' || c == ']')
            {
                if (characterStack.Count == 0 || (characterStack.Peek() != _matchingParanthesisCollection[c]))
                    return false;
                else if (characterStack.Peek() == _matchingParanthesisCollection[c])
                    characterStack.Pop();
            }
        }

        return (characterStack.Count == 0);
    }
}

class IsParanthesisMatchProgram
{
    static void Main(string[] args)
    {
        ParanthesisMatch paranthesisMatch = new ParanthesisMatch();

        do
        {
            Console.WriteLine("Please enter expression... Or Press Escape to exit... ");

            string expression = Console.ReadLine();

            Console.WriteLine("Given expression's paranthesis are {0}", paranthesisMatch.IsMatched(expression) ? " Matched" : " not Matched");

        } while (Console.ReadKey().Key != ConsoleKey.Escape);
    }
}

}