#-------------------------------------------------------------------------------
#  BubbleSort.py
#  Sorts any list whose elements are comparable
#-------------------------------------------------------------------------------

def swap(L, i, j):
   temp = L[i]
   L[i] = L[j]
   L[j] = temp
# end of swap()

def sort(L):  # implements the Bubble Sort algorithm
   for i in range(len(L)-1,0,-1):  
      for j in range(i):
         if L[j]>L[j+1]:
            swap(L, j, j+1)
         # end if
         #print("  ", L)
      # end inner for
      # print()
      #print(L)
   # end outer for
# end of function sort()
   
   
# function main() -------------------------------------------------------------
def main():
   
   A = list(range(100,0,-1))
   #A = [8,2,9,3,5,-34,67]
   #A = [4, 3, 5, 1, 2]
   #A = [5, 4, 3, 2, 1]

   print('\nbefore:')
   print(A)
   print()

   sort(A)

   print('\nafter:')
   print(A)
   print()

# end main() ------------------------------------------------------------------


# closing conditional ---------------------------------------------------------
if __name__=='__main__':

   main()

# end