type Employee		 	= String
type Spouse				= String
type Salary				= Integer
type Manager		 	= String
type Record				= (Employee, Spouse, Salary, Manager)
type DB 			 	= [Record]

overpaid			 :: DB -> [String]
overpaid []	= []
overpaid(x:xs)
	| ((getManager_R x) /= "Root" ) && ((getSalary_R x) > managerSalary ) = (getEmployee_R x):(overpaid xs)
	| otherwise = []:(overpaid xs)
	where
		managerSalary = getSalary_R (getManager_E (getManager_R x) xs) 


--grossly_overpaid	 :: DB -> [String]
--spouse_manager		 :: DB -> [String]
--spouse_manager_super ::	DB -> [String]
--super_manager		 :: DB -> [String]
--nepotism			 :: DB -> [String]
--rich				 :: DB -> [String]
--sorted_salaries		 :: DB -> [String]
--sorted_rank			 :: DB -> [String]
--sorted_worth		 :: DB -> [String]
--normalize			 :: DB -> [String]


-- Functions to get all the matching elements from type DB
allEmployee :: DB -> [String]
allEmployee [] = []
allEmployee (x:xs)	= (getEmployee_R x):(allEmployee xs)

allSpouse :: DB -> [String]
allSpouse [] = []
allSpouse (x:xs)	= (getSpouse_R x):(allSpouse xs)

allSalary :: DB -> [Integer]
allSalary [] = []
allSalary (x:xs)	= (getSalary_R x):(allSalary xs)

allManager :: DB -> [String]
allManager [] = []
allManager (x:xs)	= (getManager_R x):(allManager xs)


-- Functions to get the matching element from type Record
getEmployee_R :: Record -> String
getEmployee_R (s,_,_,_) = s

getSpouse_R :: Record -> String
getSpouse_R (_,s,_,_) = s

getSalary_R :: Record -> Integer
getSalary_R (_,_,i,_) = i

getManager_R :: Record -> String
getManager_R (_,_,_,s) = s


-- Functions to get matching element from type String, DB

getManager_E :: String -> DB -> Record
getManager [] = []
getManager_E s (x:xs)
	| s == getManager_R x = x
	| otherwise = getManager_E s xs


database0 = [("Lana Turner", "Buster Keaton", 80000, "Virginia Dare"), ("Ted Hughes", "Edna Millay", 70000, "Virginia Dare"), ("Virginia Dare", "Laurence Sterne", 100000, "Edna Millay"), ("Buster Keaton", "Lana Turner", 80000, "Ingrid Joyce"), ("James Joyce", "Ingrid Joyce", 60000, "Root"), ("Vanessa Redgrave", "Michael Redgrave", 110000, "James Joyce"), ("Michael Redgrave", "Vanessa Redgrave", 40000, "Vanessa Redgrave"), ("Edna Millay", "Ted Hughes", 70000, "Root"), ("Laurence Sterne", "Virginia Dare", 60000, "James Joyce"), ("Ingrid Joyce", "James Joyce", 60000, "Virginia Dare")]

database1 = []

database2 = [("Carol", "Eric", 200000, "Bob"), ("Fran", "Dan", 200000, "Eric"), ("Bob", "Alex", 100000, "Alex"), ("Dan", "Fran", 150000, "Carol"), ("Alex", "Bob", 100000, "Root"), ("Eric", "Carol", 300000, "Dan")]

database3 = [("Carol", "Eric", 200000, "Root"), ("Fran", "Dan", 200000, "Root"), ("Bob", "Alex", 100000, "Alex"), ("Dan", "Fran", 150000, "Root"), ("Alex", "Bob", 100000, "Root"), ("Eric", "Carol", 300000, "Root")]

-- 
database4 = [("Carol", "Eric", 200000, "Root")]