Write a program called square that prints a square of hashtag characters to standard output. The program will have a function void square (int n) { ... } that prints a square of size n. For example, if you call square (5) it will print ##### ##### ##### ##### ##### The main program will expect a single command line argument that is the size of the square. It will check for the command line argument and print a usage message if it is not present. It will then convert the argument to an int and call the square function to print the square.