class GEN_PERM
creation {ANY} 
	make
feature {ANY}

	make is
	local	
		p : ARRAY[INTEGER]
		used : ARRAY[BOOLEAN]
	
	do
		io.put_string("%N Enter size of Perm. ")
		io.read_integer
		!!p.make(1,io.last_integer)
		!!used.make(1, io.last_integer)
		io.put_string("%N The Permutations are: %N")
		All_Perms(1)
	end -- make
	
	All_Perms(k:INTEGER) is
		local
			j : INTEGER
		do
			if k > p.size then
				Print_Perm
			else
				from
					j := 1
				until
					j > p.size
				loop
					if not used.item(j) then
						p.put(j,k)
						used.put(true,j)
						All_Perms(k+1)
						used.put(false,j)
					end
					j := j+1
				end -- loop
			end
		end -- All_Perms

	Print_Perm is
	local
		k : INTEGER
	do
		from
			k := 1
		until
			k > p.size
		loop
			io.put_integer(p.item(k))
			io.putchar(' ')
			k := k+1
		end
		io.new_line
	end -- Print_Perm
end -- Gen_Perm