Verify if the given string is valid parentheses expression in c#

You are given a string with series for parentheses. The parentheses could be only of 3 opening parentheses {, (, [ and 3 closing parentheses }, ), ]. You need to figure out if the given input are valid expression or not. Valid mean if there is proper closing and opening parentheses.

Other details and algorithm can be found here. Below is the c# implementation.

http://www.geeksforgeeks.org/check-for-balanced-parentheses-in-an-expression/

	public bool IsValid(string input)
	{
	Stack<char> s = new Stack<char>();
	char[] arr = input.ToCharArray();
	int i = 0;
	bool match = false;
	while (i < input.Length)
	{
	if (arr[i] == '{' || arr[i] == '(' || arr[i] == '[')
	s.Push(arr[i]);
	if (arr[i] == '}' || arr[i] == ')' || arr[i] == ']')
	{
	if (s.Count == 0)
	{
	return false;
	}
	else if (isMatching(s.Pop(), arr[i]))
	{
	return true;
	}
	return false;
	}
	i++;
	}
	if (s.Count == 0)
	{
	return true;
	}
	return false;
	}
	private bool isMatching(char character1, char character2)
	{
	if (character1 == '(' && character2 == ')')
	{
	return true;
	}
	else if (character1 == '{' && character2 == '}')
	{
	return true;
	}
	else if (character1 == '[' && character2 == ']')
	{
	return true;
	}
	return false;
	}

view raw gistfile1.txt hosted with ❤ by GitHub