Question

Write an X86-series assembly language program that checks whether input string is palindrome or not. A palindrome is a word, number, phrase or any other sequence which reads the same backward as forward e.g. madam, racecar.

Sample Execution:

Please enter a String: redivider
The string is a palindrome

Another Sample Execution:

Please enter a String: abracadabra
The string is not a palindrome

Answer 1

//write an assembly language program that checks whether input string is palindrome or not.

ANS: In this program , iam taking a word "MADAM" as a string

Data Segment

str1 db 'MADAM','$'

strlen1 dw $-str1

strrev db 20 dup(' ')

str_palind db ' please enter a string','$'

str_palind db ' The String is a Palindrome.','$'

str_not_palind db ' The String is not a Palindrome.','$'

Data Ends

Code Segment

Assume cs:code, ds:data

Begin:

mov ax, data

mov ds, ax

mov es, ax

mov cx, strlen1

add cx, -2

lea si, str1

lea di, strrev

add si, strlen1

add si, -2

L1:

mov al, [si]

mov [di], al

dec si

inc di

loop L1

mov al, [si]

mov [di], al

inc di

mov dl, '$'

mov [di], dl

mov cx, strlen1

Palindrome_Check:

lea si, str1

lea di, strrev

repe cmpsb

jne Not_Palind

Palind:
       mov ah, 09h
       lea dx, str_palin
       int 21h
       jmp Exit

    Not_Palind:
       mov ah, 09h
       lea dx, str_not_palin
       int 21h
   Code Ends
End Begin

output:

please enter a string: MADAM

The String is a palindrome

please enter a string: abracadabra

The String is not a palindrome