Algorithms (4/14) - Read and write

Reading and writing make an algorithm (or computer program) interactive. In algorithmics, we use the functions Read() and Write() which allow this interaction. Read() retrieves user input (from the keyboard) and Write() displays messages on the screen. These two functions implement the human-computer interaction in an algorithm. If the computer program runs without taking care of these two functions of reading and writing, then it will be closed on itself and no interaction with users is possible.