brackets.cs

Brackets

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

public class Solution 
{
    public static void Main(String[] args) 
    {
        var t = Convert.ToInt32(Console.ReadLine());
        for (int a0 = 0; a0 < t; a0++)
        {
            Console.WriteLine(IsBalanced(Console.ReadLine()) ? "YES" : "NO");
        }
    }
    
    private static bool IsBalanced(string str)
    {
        var openBrackets = new Stack<char>();
        
        foreach (var ch in str.ToCharArray())
        {
            if (ch == '(' || ch == '[' || ch == '{')
            {
                openBrackets.Push(ch);
            } 
            else if (ch == ')')
            {
                if (openBrackets.Count == 0) 
                {
                    return false;
                }
                else if (openBrackets.Peek() == '(')
                {
                    openBrackets.Pop();
                }
                else
                {
                    return false;
                }
            }
            else if (ch == ']')
            {
                if (openBrackets.Count == 0) 
                {
                    return false;
                }
                else if (openBrackets.Peek() == '[')
                {
                    openBrackets.Pop();
                }
                else
                {
                    return false;
                }
            }
            else if (ch == '}')
            {
                if (openBrackets.Count == 0) 
                {
                    return false;
                }
                else if (openBrackets.Peek() == '{')
                {
                    openBrackets.Pop();
                }
                else
                {
                    return false;
                }
            }
            else
            {
            }
        }
        
        return openBrackets.Count == 0;
    }
}