Write a Python program to check if a string is a palindrome or not.
Answer:
A palindrome is a sequence of characters that read the same backwards as forwards.
Example: level, madam, refer, etc.
To check if a string is palindrome:
- First, insert all characters of the string into a stack.
- Then, using a for loop, keep popping the elements of the stack and compare them with corresponding characters of the string from the beginning.
- If at any point, there is a mismatch, then the string is not a palindrome.
Code:
def push(stack,x):
stack.append(x)
return
def pop_stack(stack):
if len(stack)==0:
return
else:
c=stack.pop()
return c
def compare(string,stack):
for i in range(len(string)):
if string[i]!= pop_stack(stack):
return False
return True
stack=[]
input_string=input("Enter a string: ")
for a in input_string:
push(stack,a)
cmp=compare(input_string,stack)
if cmp:
print("Entered string is a palindrome")
else:
print("Entered string is not a palindrome")
Output:
Enter a string: madam
Entered string is a palindrome
