python-collection/PalChecker.py at main · SuiEel/python-collection · GitHub

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class Deque (object):
   def __init__(self):
      self.items = [ ]

   def isEmpty (self):
      return self.items == [ ]

   def addRear (self, item):
      self.items.insert(0,item)

   def addFront (self, item):
      self.items.append(item)

   def removeRear (self):
      return self.items.pop (0)

   def removeFront (self):
      return self.items.pop ()

   def size (self):
      return len(self.items)


def palChecker(aString):

   chardeque = Deque()

   for ch in aString:
      chardeque.addRear(ch)

   stillEqual = True

   while chardeque.size() > 1 and stillEqual:

      first = chardeque.removeFront()
      last = chardeque.removeRear()

      if first != last:
         stillEqual = False

   return stillEqual


def main():

   while True:
      inString = input("Enter a string:" )
      if inString == "":
         break
      isPalindrome = palChecker(inString)
      if isPalindrome :
         print(inString,"is a palindrome")
      else:
         print(inString,"is not a palindrome")

main()