Consider the following informal problem description:

Many people need to know if food being served to them contains any particular ingredients that they cannot eat. Implement a function that applications can call to check whether all the dishes on a given menu are free from a specified ingredient.

What type of problem is this? Justify your answer.

Write your answer here.

(b)

Define a function that takes a menu comprising three dishes, and a specified ingredient, and outputs true if all the dishes on the menu are free from the specified ingredient. If any of the dishes on the menu contain the specified ingredient, the function outputs false.

A menu is represented as a list of three dishes.

A dish is represented as a non-empty list of non-empty strings, the first string being the name of the dish and the remaining strings being the ingredients of the dish.

A dish can have a name but no listed ingredients. Ingredients can be duplicated. If the name of the dish matches the specified ingredient, the function should output false.

For example, the menu:

Dish	Ingredients
soup	onion, potato, leek, celery
pizza	bread, tomato, cheese, cheese
banana

would be represented in Python as:

menu = [ ['soup','onion','potato','leek','celery'], ['pizza','bread','tomato','cheese','cheese'], ['banana'] ]

This example menu is not free from banana.

Function:\free_from( Inputs:\Dish,a string Preconditions:\ Output:\ containsIngredient ,a boolean **Postconditions:if

(c) (10 marks)

Add three different test cases to the following test table for the free from ingredient function, where water is the specified ingredient.

We have started with a case where all three dishes have no ingredients. State, giving a reason, whether this is an edge case.

case	menu	ingredient	output
all three dishes have no ingredients	(('potato'), ('cheese'), ('apple'))	'water'	True