using System;

public class Program

{

    public static void Main()

    {

        string inputPram ="{[()]}";

        ValidateInput validateInput = new ValidateInput();

        validateInput.IsValidStatement(inputPram);

    }

}

​

public class ValidateInput{

    public string addAssociatedClosingParanthesis(char [] stringArray, int position){

        char [] closingParanthesis = new char [] {'}',']',')'};

        string outputString = string.Empty;

        //loop through each character of input string

        for(int i =stringArray.Length - position;i > 0;i--){

            foreach (char c in closingParanthesis){

                //check if the character is opening parantesis

                if(stringArray[i] == c){

                    outputString = $"{outputString} { c}";

                }

            }

        }

        return outputString;

    }

    public bool IsValidStatement(string input){

        //standard parameters that are considered

        char [] openParanthesis = new char [] {'{','[','('};

        string outputString = string.Empty;

        //convert input string to character array

        char []  stringArray = input.ToCharArray().AsSpan();

        //loop through each charcter of input string

        for(int i =0;i < stringArray.Length-1;i++){

            foreach (char c in openParanthesis){

                //check if the character is opening parantesis

                if(stringArray[i] == c){

                    //outputString = $"{outputString} { c}";

                    string temp = addAssociatedClosingParanthesis(stringArray,c,i);

                    if(string.IsNullOrWhiteSpace(temp)){

                    return false;

                    }

                }

            }

​

        }

        return true;

    }

}

​

​