How may the following shark-fin-shaped Goal distribution be cooked up with 44 ingredients in a roll recipe R based on the roll sum of two 6-sided dice with non-standard allotments of dots?
Goal: Shark fin distribution of results calculated by R from the sum of two dice whose sides have a,b,c,d,e,f and g,h,i,j,k,l dots total dots = a+b+c+d+e+f + g+h+i+j+k+l operators = p + operand sum = q ======================================================== ingredients = total dots + operators + operand sum = a+b+c+d+e+f+g+h+i+j+k+l + p + q = 44
That is: The number 1 is served up by R from the roll sum of only 1 of the 36 possible two-die combinations; the number 2 is served up from the roll sums of just 2 combinations; and so on, up to the number 8 being served up by R from the roll sums of the remaining 8 combinations. R may serve up the same number from differently-valued roll sums.
As outlined in the shaded text box for the Goal, “ingredients” is the total of: the numbers of dots on all sides of both dice, the number of operators in the roll recipe, and the operands of those operators.
For this puzzle, “number” means an integer that is at least 0, “dice” have 6 sides, each side with a number (0 or more, as just noted) of dots, and “roll sum” is the total number of dots facing up on the two dice. Relative positions of sides on the dice are inconsequential.
A “roll recipe,” R,
consists of a series of operations with operators and operands.
Each operation revises a progressive
whose initial value is the roll sum.
The roll sum is not otherwise available in calculation.
An “operand” is a number,
n in the following list
of “operators” in play.
result is not called an operand here,
even though it technically is one,
and it only appears on one side of each operation.)
A roll recipe is in effect a set of nested parentheses
that surround a roll sum by operations and operands.
OPERATOR REVISED result + result + n addition − result − n subtraction n − result × result × n multiplication / result / n integer division (e.g, 8/3 = 2, −8/3 = −2) n / result max result max n whichever is more, result or n min result min n whichever is less, result or n
The no-computers tag means that a ✓ correct solution explains how it can be derived without a computer or unreasonable labor. Feel free, though, to use a computer for exploring or verifying a hunch, for demonstrating some limit, or for anything else interesting. Creative solutions that go outside the parameters here will receive a vote of appreciation from this puzzle’s poser.
On to examples of non-Goal distributions. For comparison to the shark fin Goal above, a familiar triangular Standard distribution with 42 ingredients is served up with no calculation on the raw roll sum of two standard dice (sides are numbered 1,2,3,4,5,6):
Standard: Unrevised roll sum of two dice with sides numbered 1,2,3,4,5,6 recipe R = [1,2,3,4,5,6 + 1,2,3,4,5,6] total dots = 42 = 1+2+3+4+5+6 + 1+2+3+4+5+6 operators = 0 + operand sum = 0 ====================== ingredients = 42
An Almost-shark-fin distribution may be cooked up with 53 ingredients by taking the roll sum of two standard dice, again, but now subtracting 1 from it and capping that at 8 :
Almost: recipe R = ([1,2,3,4,5,6 + 1,2,3,4,5,6] − 1) min 8 \__________/ operations total dots = 42 = 1+2+3+4+5+6 + 1+2+3+4+5+6 operators = 2 = "−" "min" + operand sum = 9 = 1 + 8 ====================== ingredients = 53
The same Almost distribution may be cooked up with a Better roll recipe that has many fewer ingredients by numbering the dice 0,1,1,2,2,3 and 0,2,3,4,5,7, capping their roll sum at 7, and adding 1 to that :
Better: recipe R = ([0,1,1,2,2,3 + 0,2,3,4,5,7] min 7) + 1 total dots = 30 = 0+1+1+2+2+3 + 0+2+3+4+5+7 operators = 2 = "min" "+" + operand sum = 8 = 7 + 1 ====================== ingredients = 40
Open-ended Bounty challenge, apparently resolved:
Fewest ingredients to cook up a shark fin Goal distribution
with a roll recipe R that has only one operation (
operators = 1).
At post time the secret Bounty recipe to beat has 74 ingredients.
Even without beating the initial secret Bounty recipe,
has earned two bounties with
that (unless someone happens to notice an oversight in the approach):
(a) lists all 1-operation roll recipes of 74 ingredients,
going on to prove that fewer ingredients will not suffice,
and (b!) serendipitously proves that no solution exists directly from
a no-recipe raw roll sum, which is quite a relief for this puzzle’s poser.