Question

Write a program that uses a stack to test input strings to determine whether they are palindromes. A palindrome is a sequence of characters that reads the same as the sequence in reverse; for example, noon.

Answer 1

Answer:

Here the code is given as follows,

Explanation:

def isPalindrome(x):

   stack = []

   #for strings with even length

   if len(x)%2==0:

       for i in range(0,len(x)):

           if i<int(len(x)/2):

               stack.append(x[i])

           elif stack.pop()!=x[i]:

               return False

       if len(stack)>0:

           return false

       return True

   #for strings with odd length    

   else:

       for i in range(0,len(x)):

           if i==int(len(x)/2):

               continue

           elif i<int(len(x)/2):

               stack.append(x[i])

           elif stack.pop()!=x[i]:

               return False

       if len(stack)>0:

           return false

       return True  

def main():  

   while True:  

       string = input("Enter a string or Return to quit: ")  

       if string == "":  

           break  

       elif isPalindrome(string):  

           print("It's a palindrome")  

       else:  

           print("It's not a palindrome")  

if __name__ == '__main__':  

   main()