Practice: (In C language) Extend the functionality of Stack data structure by defining a new function PeekAt which just returns the value at a specific position of the stack (without changing the content of the stack). Write a program that asks the user to enter a string containing parenthesis. Then your program determines if the parenthesis are balanced in the string. Do the previous task but support all kind of brackets including ({[.For exampl 2 * { 4+ [ 3 2 ] +(6/7) } is a balanced input Write a program that asks the user to enter a string with the pattern a'bmchum. For example, aabbbccccc is a valid input. The program should tell the user whether the input is matched with the pattern or not