Return to Answer

J, 16 19 12 characters

*/@$~/1,~$~/ 

or as a verb (17 characters):

h=:[:*/@$~/1,~$~/ 

usage:

 h 2 4 65536 

or taking input from keyboard (24 27 20 characters):

*/@$~/1,~$~/".1!:1]1 

with thanks to FUZxxl for pointing out my stupidity. :-)

Explanation:

J is read from right to left, so using 2 4:

/ is used to insert the verb $~ between each pair of items in the list. $~ takes the left item and shapes it $ using the right item (the ~ reverses the arguments) - so this would be equivalent to 4 $ 2 which gives you a list of 2s which is four items long 2 2 2 2.

Now we append 1 to the list 1,~ and then do the same thing again; / insert a verb */@$~ between each pair of items in the list. This verb starts in the same way $~ but this time it / inserts a * between each item of the newly generated list. The @ just makes sure that the */@$~ works as one verb instead of two. This gives 2 multiplied by itself enough times to be equivalent to 2^4.

J's vocabulary page - I find solving problems with J fun just because of the different way it sometimes does things.

Adding one further iteration to remove the * operator has 2 problems

• It comes out at 17 characters (+/@$~/,@$~/1,~$~/) which, even with the -5 bonus, is too long
• It runs out of memory if the number gets too large so doesn't meet the requirement of being able to calculate 4 3

J, 16 19 12 characters

*/@$~/1,~$~/ 

or as a verb (17 characters):

h=:[:*/@$~/1,~$~/ 

usage:

 h 2 4 65536 

or taking input from keyboard (24 27 20 characters):

*/@$~/1,~$~/".1!:1]1 

with thanks to FUZxxl for pointing out my stupidity. :-)

Explanation:

J is read from right to left, so using 2 4:

/ is used to insert the verb $~ between each pair of items in the list. $~ takes the left item and shapes it $ using the right item (the ~ reverses the arguments) - so this would be equivalent to 4 $ 2 which gives you a list of 2s which is four items long 2 2 2 2.

Now we append 1 to the list 1,~ and then do the same thing again; / insert a verb */@$~ between each pair of items in the list. This verb starts in the same way $~ but this time it / inserts a * between each item of the newly generated list. The @ just makes sure that the */@$~ works as one verb instead of two. This gives 2 multiplied by itself enough times to be equivalent to 2^4.

J's vocabulary page - I find solving problems with J fun just because of the different way it sometimes does things.

Adding one further iteration to remove the * operator has 2 problems

• It comes out at 17 characters (+/@$~/,@$~/1,~$~/) which, even with the -5 bonus, is too long
• It runs out of memory if the number gets too large so doesn't meet the requirement of being able to calculate 4 3

J, 16 19 12 characters

*/@$~/1,~$~/ 

or taking input from keyboard (24 27 20 characters):

*/@$~/1,~$~/".1!:1]1 

with thanks to FUZxxl for pointing out my stupidity. :-)

Explanation:

J is read from right to left, so using 2 4:

/ is used to insert the verb $~ between each pair of items in the list. $~ takes the left item and shapes it $ using the right item (the ~ reverses the arguments) - so this would be equivalent to 4 $ 2 which gives you a list of 2s which is four items long 2 2 2 2.

Now we append 1 to the list 1,~ and then do the same thing again; / insert a verb */@$~ between each pair of items in the list. This verb starts in the same way $~ but this time it / inserts a * between each item of the newly generated list. The @ just makes sure that the */@$~ works as one verb instead of two. This gives 2 multiplied by itself enough times to be equivalent to 2^4.

J's vocabulary page - I find solving problems with J fun just because of the different way it sometimes does things.

Adding one further iteration to remove the * operator has 2 problems

• It comes out at 17 characters (+/@$~/,@$~/1,~$~/) which, even with the -5 bonus, is too long
• It runs out of memory if the number gets too large so doesn't meet the requirement of being able to calculate 4 3

J, 16 19 12 characters

*/@$~/1,~$~/ 

or as a verb (17 characters):

h=:[:*/@$~/1,~$~/ 

usage:

 h 2 4 65536 

or taking input from keyboard (24 27 20 characters):

*/@$~/1,~$~/".1!:1]1 

with thanks to FUZxxl for pointing out my stupidity. :-)

Explanation:

J is read from right to left, so using 2 4:

/ is used to insert the verb $~ between each pair of items in the list. $~ takes the left item and shapes it $ using the right item (the ~ reverses the arguments) - so this would be equivalent to 4 $ 2 which gives you a list of 2s which is four items long 2 2 2 2.

Now we append 1 to the list 1,~ and then do the same thing again; / insert a verb */@$~ between each pair of items in the list. This verb starts in the same way $~ but this time it / inserts a * between each item of the newly generated list. The @ just makes sure that the */@$~ works as one verb instead of two. This gives 2 multiplied by itself enough times to be equivalent to 2^4.

J's vocabulary page - I find solving problems with J fun just because of the different way it sometimes does things.

Adding one further iteration to remove the * operator has 2 problems

• It comes out at 17 characters (+/@$~/,@$~/1,~$~/) which, even with the -5 bonus, is too long
• It runs out of memory if the number gets too large so doesn't meet the requirement of being able to calculate 4 3

J, 16 19 12 characters

*@/$~/1,~$~/ 

or taking input from keyboard (24 27 20 characters):

*/@$~/1,~$~/".1!:1]1 

with thanks to FUZxxl for pointing out my stupidity. :-)

Explanation:

J is read from right to left, so using 2 4:

/ is used to insert the verb (]$[) between each pair of items in the list. (]$[) takes the left item ] and shapes it $ using the right item [ - so this would be equivalent to 2 $ 4 which gives you a list of 2s which is four items long 2 2 2 2.

Now we append 1 to the list and then do the same thing again; / insert a verb ([:*/]$[) between each pair of items in the list. This verb starts in the same way ]$[ but this time it / inserts a * between each item of the newly generated list. The [: just makes sure that the */ is used in its monadic form instead of its dyadic form. This gives 2 multiplied by itself enough times to be equivalent to 2^4.

J's vocabulary page - I find solving problems with J fun just because of the different way it sometimes does things.

Adding one further iteration to remove the * operator has 2 problems

• It comes out at 17 characters (+/@$~/,@$~/1,~$~/) which, even with the -5 bonus, is too long
• It runs out of memory if the number gets too large so doesn't meet the requirement of being able to calculate 4 3

J, 16 19 12 characters

*/@$~/1,~$~/ 

or taking input from keyboard (24 27 20 characters):

*/@$~/1,~$~/".1!:1]1 

with thanks to FUZxxl for pointing out my stupidity. :-)

Explanation:

J is read from right to left, so using 2 4:

/ is used to insert the verb $~ between each pair of items in the list. $~ takes the left item and shapes it $ using the right item (the ~ reverses the arguments) - so this would be equivalent to 4 $ 2 which gives you a list of 2s which is four items long 2 2 2 2.

Now we append 1 to the list 1,~ and then do the same thing again; / insert a verb */@$~ between each pair of items in the list. This verb starts in the same way $~ but this time it / inserts a * between each item of the newly generated list. The @ just makes sure that the */@$~ works as one verb instead of two. This gives 2 multiplied by itself enough times to be equivalent to 2^4.

J's vocabulary page - I find solving problems with J fun just because of the different way it sometimes does things.

Adding one further iteration to remove the * operator has 2 problems

• It comes out at 17 characters (+/@$~/,@$~/1,~$~/) which, even with the -5 bonus, is too long
• It runs out of memory if the number gets too large so doesn't meet the requirement of being able to calculate 4 3