Programming challenge description: given a string comprising just of the characters {,},[,] determine if it is well-formed or not. input: your program should read lines from standard input. each line contains a string comprising of the characters mentioned above. there is no whitespace between characters. output: print out true if the string is well-formed, false otherwise.

Employing Java language,

Explanation:

//for using stack data structure

import java.util.Stack;

//class definition

public class BracketMatch {

   //function to find the string is well formed or not

   public static boolean isWellFormed(String str) {

       //variable to store the character value

       char ch;

       //check if the first character itself is the end of the brackets

       if (str.charAt(0) == ')'||str.charAt(0) =='}'||str.charAt(0) ==']')

           return false;

       //creating a stack of character type

       Stack<Character> stack = new Stack<Character>();

       //iterating through the characters in string

       for(int i=0; i < str.length(); i++) {

           //storing the current character from the string in the variable

           ch = str.charAt(i);

           if(ch == '('||ch=='{'||ch=='[')

               //if the character is starting of the brackets push it into stack

               stack.push(ch);

           else if(ch == ')')

               //if it is closing bracket and the stack is empty then the string is not well formatted

               if(stack.empty())

                   return false;

               else if(stack.peek() == '(')

                   stack.pop();

               else

                   return false;

           else if(ch == '}')

               if(stack.empty())

                   return false;

               else if(stack.peek() == '{')

                   stack.pop();

               else

                   return false;

       }

       //returning the stack content, if the string will be well formed the stack would be empty

       //after all the operations

       return stack.empty();

   }

   //main method

   public static void main(String[] args) {

       //calling function to find if the string is welll formatted or not

       System.out.println(isWellFormed("{}"));

       //calling function to find if the string is welll formatted or not

       System.out.println(isWellFormed("([)]"));

   }

}

you can not change you age soon as you signed up. the only way is too delete your account and use another account to sign up and put your correct age.

which functions return a valid value without any arguments?

(-blank- and -blank- return a valid value without any arguments.)

1st -blank-

today

sqrt

count

2nd -blank-

round

now

sqrt