Problem Statement

Given   M   as a list of items and another list   N   of items chosen from   M,   create   M'   as a list with the first occurrences of items from   N   sorted to be in one of the set of indices of their original occurrence in   M   but in the order given by their order in   N. That is, items in   N   are taken from   M   without replacement, then the corresponding positions in   M'   are filled by successive items from   N.

The words not in   N   are left in their original positions.

If there are duplications then only the first instances in   M   up to as many as are mentioned in   N   are potentially re-ordered.

Is ordered as:

Show the output, here, for at least the following inputs:

Let's start with the solution:

(lib 'list) ;; for list-delete

(define dataM
'((the cat sat on the mat)
(the cat sat on the mat)
(A B C A B C A B C)
(A B C A B D A B E)      
(A B)                    
(A B)                    
(A B B A)))               
		
(define orderM
'((mat cat)
(cat mat)
(C A C A)
(E A D A)
(B)      
(B A)    
(B A)))

(define (order-disjoint M N)
(define R (append N null)) ;; tmp copy of N : delete w when used
	(for/list [(w M)]
	(if
		(not (member w R)) w ;; output as is
		(begin0
		(first N) ;; replacer
		(set! N (rest N))
		(set! R (list-delete R w))))))