Maximum difference between adjacent elements of list

Maximum difference between adjacent elements of list is a draft programming task. It is not yet considered ready to be promoted as a complete task, for reasons that should be found in its talk page.

Task

Find maximum difference between adjacent elements of list.

The list may have a negative value, a zero value, a real number.
List = [2, -3 ,0, 1, 1, -2.3, 0, 5.5, 8, 6, 2, 9, 11, 8, 1]

Ring

<lang ring> see "working..." + nl strList = "[2,-3,0,1,1,-2.3,0,5.5,8,6,2,9,11,8,1]" see "Maximum difference between adjacent elements of list is:" + nl + nl see "Input list = " + strList + nl + nl see "Output:" + nl sList = [2,-3,0,1,1,-2.3,0,5.5,8,6,2,9,11,8,1] oldDiff = fabs(sList[1]-sList[2]) first = sList[1] second = sList[2] sortList = [] add(sortList,[oldDiff,first,second])

for n = 1 to len(sList)-1

   diff = fabs(sList[n]-sList[n+1])
   oldDiff = diff
   first = sList[n]
   second = sList[n+1]
   add(sortList,[oldDiff,first,second])

next

sortList = sort(sortlist,1) sortList = reverse(sortlist)

for n=1 to len(sortList)-1

   oldDiff1 = sortlist[n][1]
   oldDiff2 = sortlist[n+1][1] 
   first1 = sortlist[n][2]
   second1 = sortlist[n][3]
   first2 = sortlist[n+1][2]
   second2 = sortlist[n+1][3]
   if n = 1 and oldDiff1 != oldDiff2
      see "" + first1 + "," + second1 + " ==> " + oldDiff1 + nl 
   ok
   if oldDiff1 = oldDiff2
      see "" + first1 + "," + second1 + " ==> " + oldDiff1 + nl   
      see "" + first2 + "," + second2 + " ==> " + oldDiff2 + nl
   else
      exit
   ok

next

see "done..." + nl </lang>

Output:

working...
Maximum difference between adjacent elements of list is:

Input list = [2,-3,0,1,1,-2.3,0,5.5,8,6,2,9,11,8,1]

Output:
2,9 ==> 7
8,1 ==> 7
done...

XPL0

<lang XPL0>real List, Dist, MaxDist; int I; [List:= [2., -3., 0., 1., 1., -2.3, 0., 5.5, 8., 6., 2., 9., 11., 8., 1.]; MaxDist:= 0.; for I:= 0 to 15-2 do

   [Dist:= abs(List(I) - List(I+1));
   if Dist > MaxDist then
       MaxDist:= Dist;
   ];

RlOut(0, MaxDist); ]</lang>

Output:

    7.00000