this is terrible, but it'll probably work

mattslist.py

# actually not python, just pseudocode highlighted like python.

if( len(ints) < 2 )     # if the list is short, just exit
   return

for (i=1; i < len(ints)-1; ++i):  # for each of the list entries, from the second to the second to last
   if ints[i] == ints[i-1] or ints[i] == ints[i+1]:  # if the entry to the left or entry to the right is equal to the current one
       ints[i] = ints[i] + 1   # add one to the current one
       i = i - 1               # set the cursor back one, because continuing/looping again will cause it to move forward
       continue                # repeat the loop to make sure our +1 change was ok.

actually not python, just pseudocode highlighted like python.

if( len(ints) < 1 )
return

for (i=1; i < len(ints)-1; ++i):
if ints[i] == ints[i-1] or ints[i] == ints[i+1]:
ints[i] = ints[i-1] + inst[i+1]
continue