Solve hanging lantern problem: Difference between revisions

=={{header|J}}==

Translation of [[#APL|APL]]:

<lang J>lanterns=: {{ (!+/y) % */!y }}<</lang>

Example use:

<lang J> lanterns 1 2 3

60

lanterns 1 3 3

140

</lang>

Also, a pedantic version where we must manually count how many values we are providing the computer:

<lang J>pedantic=: {{

assert. ({. = #@}.) y

lanterns }.y

}}</lang>

And, in the spirit of providing unnecessary but perhaps pleasant (for some) overhead, we'll throw in an unnecessary comma between this count and the relevant values:

<lang J> pedantic 3, 1 2 3

60

pedantic 3, 1 3 3

140</lang>

If we wanted to impose even more overhead, we could insist that the numbers be read from a file where tabs, spaces and newlines are all treated equivalently. For that, we must specify the file name and implement some parsing:

<lang J>yetmoreoverhead=: {{

pedantic ({.~ 1+{.) _ ". rplc&(TAB,' ',LF,' ') fread y

}}</lang>

Examples of this approach are left as an exercise for the user.