## jesssica 3 years ago WHO LIKES CHICKEN NUGGETS? help with writing a c++ program that outputs diff combinations of chicken nugget packs...

1. jesssica

the problem is the nuggets come in packs of 6 9 and 20 and i have to make a program that outputs the different pack combinations that the user can buy for an order. for example,

have you written any code for it?

3. jesssica

if the user wanted 54 nuggets, they could have nine packs of six or five packs of nine.

4. jesssica

*six packs of nine.

5. bahrom7893

Ohhh i see

6. jesssica

and yeah i didnt write code yet. i am still stuck on making a plan...

7. bahrom7893

this is like finding the factors...

8. bahrom7893

pulling up old codes for ideas...

this is pset2 from 6.00 and i have done it.

10. jesssica

do i have to do something with the %.

no, first try to write a simple code or read the problem again

12. jesssica

ummm. i am so stuck. do i just write out all the combinations myself ?

13. jesssica

oh and there is a cap of 100.

i am not able to tell you clearly about it since you have not written any code.

15. bahrom7893

ok let's start with basics: #include <iostream> using namespace std; int main() { int amt; cout << "How many nuggets would you like to purchase?" << endl; cin >> amt; ...... hmm now

16. bahrom7893

oh btw the user has to buy something that's a multiple of these. I mean what if he buys less than 6, or what if he buys 7, or 8, etc.

then it cannot be bought

18. bahrom7893

So i guess we could add the following: do { cout << "Please choose a different number: " cin >> ant; } while (a%6!=0 || a%9!=0 || a%20!=0 );

19. jesssica

#include <iostream> #include <iomanip> using namespace std; void main() { int p6, p9, p20, order; cout<<"How many nuggets would you like to order?"; cin>>order; p20=order/20; cout<<p20<<" 20 piece package."<<endl; } kay there. so that works for if i input 20. lol.

20. bahrom7893

lol that's like... *facepalm*

you guys are using c++, but i wrote it in python

22. jesssica

this is why i need help.

23. bahrom7893

jask, give me the algorithm, i'll try to translate it.

ok i'll give you the most basic version of this program

here """To find the sizes of McNuggets packages""" from math import * number = input("Enter the number of McNuggets you want to buy :") a=b=c=1 available = True while available == True: a1=number/a + 1 b1=number/b + 1 c1=number/c + 1 for a in range(0,a1): for b in range(0,b1): for c in range(0,c1): if number == 6*a + 9*b + 20*c : print "you need",a,"number of",6,"packs" print "you need",b,"number of",9,"packs" print "you need",c,"number of",20,"packs" print "of McNuggets" print "---------------------------" available=False print "Thank you for Buying and Have a nice day!!!" break

this for the first time i wrote it, a long time ago

it may not be that much elegant but it works, not for every input

28. jesssica

okay so why are we dividing by the variable plus 1?

29. bahrom7893

oh boy, i hoped it would work for all inputs, i mean come on, i can write out like 50 if else statements too for all possible inputs..

30. jesssica

that ^^

31. bahrom7893

there's no way in heck im doin that lol.. let me think

32. bahrom7893

okay i see...

33. jesssica

at least 6 9 and 20 multiples can be done with, for example, an if (order%6==0) p6=order/6; cout<<p6 "6-piece packages."<<endl; etc

34. bahrom7893

writing the code in a compiler.. not sure if the right idea.. just yet

okay @bahrom7893 this solution is only for this specific problem, i also have a more general solution

36. arcticf0x

I wish i could've helped you with the code, but still i found this http://en.wikipedia.org/wiki/Coin_problem#McNugget_numbers hope that helps!

37. bahrom7893

is that federer?

38. jesssica

aw thankss.

39. bahrom7893

mehh my method didnt work

in fact this program can be generalized too, just take input three packet sizes from user and replace them with 6, 9, 20 and there you have it.

41. jesssica

so ask the user to guess first?

the packet sizes as well as the number of mcnuggets they want.

43. arcticf0x

@bahrom7893 Yep, Roger Federer :D

This problem (albeit in python) is on one of the problem sets for course 6.00, problem set 2 to be precise. So you might want to ask there. I've done it, and could give you my code, but it's really basically the same as jaskaran's.

the reason you divide by the variable is because, for example, if you have a box of nuggets with 20 pieces, you know that the maximum number of boxes you could have (and thus the maximum you need to test) is your target/20. As for the +1, it's because the python range function gives you numbers until one behind the number you input, e.g.: range (0,5) 0, 1, 2, 3, 4 C++ may or may not be similar.

46. jesssica

does python solve for a b and c in that equation num==2*a + 9*b + 20*c ? cause i dont think c++ does .

47. jesssica

okay i am trying to understand jaskarans program...if the input was 6, then how would it print b and c as 0 if they were initialized as 1 ?

I think the reason he put in the line a=b=c=1 is just to initialize them as numbers. But actually I don't think it really matters, since either way you're simply looking at a, b and c values iterated between 0 and number/(size of nugget box). I'll paste my code for it, as upon second look mine is a little different (I don't use a while loop for example) and a bit simpler, and also mine has annotations that might make it more easy to understand. Anyway, here's mine: http://pastebin.com/dpJuFujR Actually I disagree with jaskarans' use of the while loop because, upon a cursory glance, it seems to be irrelevant: the value starts as true, the for statements run, and then the value is false. The program would run just as well without any while statement. As for what you asked, no, python doesn't actually solve (algebraically) the equation as you said. I'm sure you can write a program that solves algebraic equations, but the much more simple answer when dealing with a program language is to use what a computer is good at: trying out a bunch of stuff at blazing speed and testing if it's the right answer.

As a matter of fact, looking back at my program now, the S=0 M=0 L=0 statements I made at the beginning are also irrelevant. S, M, and L values are chosen by the for function, so even if I had not mentioned them at all in the beginning it still wouldn't matter.

50. jesssica

i guess python and c++ work differently because i tried translating yours and it is giving me a neverending loop. i am not sure c++ is capable of checking the range by itself.. idk. thanks though !

51. pre-algebra

This is naturally a recursive problem, and since it's a Sunday evening and I'm bored, I wrote this little hack that solves your problem: http://ideone.com/2iYBp

52. arcticf0x

@pre-algebra It works! But not for all inputs. Also please could you explain this part http://ideone.com/01WcK Thanks!

jesssica - there shouldn't be any possibility of an infinite loop occurring with only for statements; they have a strict beginning and end. Or at least, Python is that way and I would assume C++ is as well. Are you sure you're not using a while statement or other loop-generating code?

54. jesssica

thanks everyone, i ended up using mod and an else of subtracting from the initial and remainders.