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January 29th, 2013, 12:56 PM

FallOutBoy

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Help

i've been asked to make this program and i have no idea where to even start

This lab is based on the same idea as lab 1: We have a list of integers, representing the yearly profit (in kilo euro) of n businesses (shops) along the high street in the City centre. This time we are being given 4 (four) businesses ("for free"), that neighbor one another. The problem is to calculate which 4 we should take to maximize our yearly profit.
Given these numbers, write a PYTHON program to calculate which 4 we should take. As examples:

If the profits were 52, 67, -8, 43, -20 we should take the first 4 businesses.
If the profits were -20, 36, -10, -30, 3, 21 we would take no business (this is also allowed).

January 29th, 2013, 01:44 PM

b49P23TIvg

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In general you want to maximize the sum of m consecutive numbers from a list of n, m <= n . Executable Iverson notation has an infix adverb that simplifies this task. 4&(+/\) means
4 \ apply the verb to length 4 infixes
/ insert the verb
+ add

Thus, insert add to prefixes of length 4.

Code:

                            A  NB. data
52 67 _8 43 _20

                      4 +/\ A  NB. sum of length 4 infixes
154 82

                  >./ 4 +/\ A  NB. maximum of these sums
154

             (i. >./) 4 +/\ A  NB. index of maximum  (starting position)
0

   ((] , {~) (i. >./)) 4 +/\ A  NB. index and maximum
0 154
   


   B
_20 36 _10 _30 3 21

   ((] , {~) (i. >./)) 4 +/\ B  NB. index and maximum
1 _1

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January 29th, 2013, 01:52 PM

leeuw01

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Your question is not very clear to me. If I understand it correctly you need to calculate which 4 adjacent numbers give the biggest sum. If you want to do it easy, just add every value in a list, then use a to calculate every possibility.

Here's how you could do it:

Code:


List[52, 67, -8, 43, -20]
A = len(list)
x = 0
While x < A-3:
	B = List[x]+List[x+1]+List[x+2]+List[x+3]
	If D < B:
		D = B
		E = X
	x = x + 1


print (List[e], List[e+1], List[e+2], List[e+3])

January 29th, 2013, 02:12 PM

FallOutBoy

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Quote:

Originally Posted by leeuw01

Code:


List[52, 67, -8, 43, -20]
A = len(list)
x = 0
While x < A-3:
	B = List[x]+List[x+1]+List[x+2]+List[x+3]
	If D < B:
		D = B
		E = X
	x = x + 1


print (List[e], List[e+1], List[e+2], List[e+3])

Thanks

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