python - Finding the maximum sum of elements of a given array -

i have find maximum sum of elements in array (or permuted form), value of elements depends upon position in array

an algorithm finding sum of particular array follows

int taste = 0 (int i= 0; <= n; i++){     if (p[i]) - p[i-1]) >= 0):         taste += * (p[i]) - p[i - 1])     else:         taste += * (p[i - 1] - p[i]) 

my solution in python getting result 0

from itertools import permutations def sum_permuatations ():     t = int(input())     taste = 0     maxtaste = 0     while ( t!=0):         t = t-1         lent = input()         lis = input()          p in permutations(lis, len(lent)):             in range(2,len(p)+1):                 if (int(p[i]) - int(p[i-1]) >= 0):                     taste += i*(int(p[i])-int(p[i-1]))                 else:                     taste += i*(int(p[i-1])- int(p[i]))             if taste > maxtaste:                 maxtaste = taste         return maxtaste 

please me resolving error in code.

this solution uses itertools library generate various permutations. each of max adjacent sum formula calculated using zip give consecutive pairs of numbers in list. enumerate function used give position of each pair.

import itertools  input_list = [10, 15, 16] result = []  perm in itertools.permutations(input_list):     sum_diff = 0     i,pair in enumerate(itertools.izip(perm[:-1], perm[1:])):         sum_diff += abs(pair[0]-pair[1]) * (i+2)     result.append((sum_diff, perm))  result.sort() print result[-1] 

which give following result:

(28, (15, 10, 16)) 

or if print whole list:

[(13, (10, 15, 16)), (15, (10, 16, 15)), (17, (16, 15, 10)), (20, (15, 16, 10)), (27, (16, 10, 15)), (28, (15, 10, 16))] 

your solution has couple of minor issues, using range start 0. taste needs zeroed each permutation follows:

from itertools import permutations  def sum_permuatations(lis):     maxtaste = 0      p in permutations(lis):         taste = 0         in range(1,len(p)):             if (int(p[i]) - int(p[i-1]) >= 0):                 taste += (i+1)*(int(p[i]) - int(p[i-1]))             else:                 taste += (i+1)*(int(p[i-1]) - int(p[i]))          if taste > maxtaste:             maxtaste = taste      return maxtaste  input_list = [10, 15, 16] print sum_permuatations(input_list)  

you need edit prompt input, made easier test. edit use abs command avoid needing subtraction in different order.