Validation of Input string With balanced parentheses

Validation of Input string With balanced parentheses- Learn how to write a program to find  a string of parentheses is valid or not.

For Example Consider the following Inputs with balanced parentheses.

Input-1

{}{}

output-1
valid string

Input-2

}{{}}

0utput-2

invalid string

Note

For valid string , parentheses must be open  and need to have closed parentheses for the opened one.

C# -Program to find whether the string with balanced parentheses is valid or invalid

  class Program
    {
        static void Main(string[] args)
        {
               //input string for validation
            String s = "{{{}}}";
            int counter = 0;
            
             //counter variable increments if character is '{ ' and 
            //counter variable decrements if character is '}'
            //finally for every balanced open parenthesis , it required a closed parenthesis as a rule.
            //if for every balanced open parenthesis finds corresponding balanced closed parenthesis
            // then counter becomes zero which is a valid string 
            //if counter less than zero then it is a invalid string.
            
            for (int i = 0; i <s.Length ; i++)
            {
                if(s[i]=='{')
                {
                    counter++;
                }
                if(s[i]=='}')
                {
                    counter--;
                    if(counter<0)
                    {
                        break;
                    }
                    
                }
            }
            if(counter==0)
            {
                Console.WriteLine("valid string ");
            }
            if(counter < 0)
            {
                Console.WriteLine("in valid string ");
            }
        }
    }

Output
valid string