Checking string has balanced parentheses

Question

I am reading the Algorithm Design Manual Second Edition and this is from an exercise question. Quoting the question

A common problem for comp

Answer 1

Piggy back on @Russell's idea:

public class BalancedBrackets
{
    private readonly char[] _leftBrackets = new char[] {'[', '(', '{', '<'};
    private readonly char[] _rightBrackets = new char[] {']', ')', '}', '>'};

    public bool IsBalanced(string input)
    {
        int count = 0;
        foreach (var character in input.ToCharArray())
        {
            if (_leftBrackets.Contains(character)) count++;
            if (_rightBrackets.Contains(character)) count--;
        }
        return count == 0;
    }
}