Answer:
//program_start
//variable_inicialization
books = 0
maps = 0
magazines = 0
//End variable_inicialization
//operation_selection_routine
display "Select operation: (I) for input item to stock, (O) for output items in stock
operation = read_keyboard_input
IF (operation = "I")
goto input_routine
ELSE IF (operation = "O")
goto output_routine
ELSE
display "Incorrect option, try again"
goto operation_selection_routine
ENDIF
//End operation_selection_routine
//input_routine
display "Insert item code to add to stock"
input_code = read_keyboard_input
IF (input_code >= 1000 & input_code < 2000)
IF (input_code NOT duplicated_in_stock)
add_to_stock (input_code)
books = books + 1
display "Book added"
ELSE
display "Item Code is already present in stock"
ENDIF
ELSE IF (input_code >= 2000 & input_code < 3000)
IF (input_code NOT duplicated_in_stock)
add_to_stock (input_code)
maps = maps + 1
display "Map added"
ELSE
display "Item Code is already present in stock"
ENDIF
ELSE IF (input_code >= 3000 & input_code < 4000)
IF (input_code NOT duplicated_in_stock)
add_to_stock (input_code)
magazines = magazines + 1
display "Magazine added"
ELSE
display "Item Code is already present in stock"
ENDIF
ELSE IF (input_code = 9999)
goto program_end
ELSE
display "Incorrect option, try again"
goto input_routine
ENDIF
goto operation_selection_routine
//End input_routine
//output_routine
display "Items in stock"
display "Number of books: " + books
display "Number of maps: " + maps
display "Number of magazines: " + magazines
goto operation_selection_routine
//End output_routine
//program_end
display "Terminating stock program"
stop_program
Explanation:
Pseudo code is a way to design an algorithm using normal words and terms, that are not specific to any programming language. It is easier to understand how the program works and once finished, can be translated to the desired programming language.
This algorithm uses 5 blocks of code:
*variable_inicialization, where item counters are initially set to zero.
*operation_selection_routine, where the program request user input to select if the user will add an item or show existing items in stock. If an incorrect option is given, it will repeat this same routine.
*input_routine, the program will request the four digit code to add, and will check if it is not already present (to avoid duplicated items), and if the item code belongs to a book, map or magazine, increasing the corresponding item counter. Also, if the code is 9999 it will go to the program_end routine, otherwise it will display an error message and request a new item code. After a valid item code it will return to the operation_selection_routine.
*output_routine, it will display on screen the number of items for each category. Then, returns to the operation_selection_routine.
*program_end, it will simply display a goodbye message and terminate the program.
