Question

Programming Paradigms , using Haskell !!!!

I need help on this problem , Intersection of list of list HASKELL

I need to use my own definition for intersection . Its my homework assignment.

example like :

intersection [ [2, 8, 6, 5, 8, 8, 8], [8, 8, 1, 1, 4, 8], [3, 3, 8, 10, 8, 10, 8, 7, 8, 8, 3]]

Output: [8, 8, 8]

intersection [ [1, 2, 3, 4], [5, 6, 7], [8], [9, 10]]

Output: [ ]

I discovered that exists a function intersect :: Eq a => [a] -> [a] -> [a] ( but it's available only for 2 lists)

Answer 1

You need to find your current intersection result and intersect it with next list until you run out of lists or till it becomes empty.

One way is could be merge sort, it's one kind of intersection but would be more complicated.

One neat way is :

 > import Data.List > foldl1 intersect [X,Y,Z] ANSWER

Reference: https://hackage.haskell.org/package/base-4.12.0.0/docs/Data-List.html

https://riptutorial.com/haskell/example/7552/merge-sort