Assignment 1: mystring functions

declare a structure named mystring containing a char array of 20 bytes and an 
integer containing the length of the string contained.

write the following three functions

void stringinput( mystring& s );
void stringoutput( const mystring& s );
void stringcopy( mystring& dest, const mystring& src );

where the input function gets a new string from the user and places it in the
passed object. the output functions prints the string in the passed object on
the console. and the copy function copies the string and its length from the 
source structure to the destination structure.

declare an array of five mystrings in main, get them via the user using a loop
calling stringinput. test the other functions as well from the main.

WORK INDEPENDENTLY AND DO NOT DISCUSS WITH EACH OTHER AT ALL