Thread: Palindrome Function

Hey all,

So I'm trying to write a program that takes a 5 letter word and displays it as a palindrome with a space between each letter. I can do this in only 11 lines of code, however I need a function part to the program and I'm not sure what this function should do or how to modify my code to fix it? This is what I have so far.

Code:

#include <stdio.h>
#include <stdlib.h>

char palindrome(char word);
char main(void)
{
char palin;
 char letter0, letter1, letter2, letter3, letter4;
   printf("What is the five letter word? ");
    scanf("%c",&letter0);
    scanf("%c",&letter1);
    scanf("%c",&letter2);
    scanf("%c",&letter3);
    scanf("%c",&letter4);

palin = palindrome(letter0, letter1, letter2, letter3, letter4);
printf("Here is the palindrome:\n", palin);
    return 0;
}

char palindrome(char word)
{
char letter0, letter1, letter2, letter3, letter4;
char pDrome[50];
pDrome == printf("%c %c %c %c %c %c %c %c %c", letter0, letter1, letter2, letter3, letter4, letter3, letter2, letter1, letter0);
return pDrome;

}

I suggest you get your textbook and brush up on your C basics. There are also some tutorials on this site to help out too:

1. Functions
2. Arrays
3. Strings

A quick summary of the problems you have:

1. Your palindrome function needs to take 5 letters as parameters, not one.
2. == compares two things, a single = assigns a value.
3. You can't return an entire local array from a function. Allocate dynamically or pass in an array to fill/modify.
4. Read the printf docs on how to use format specifiers, namely %s.
5. char is for individual characters. You need a char * or a char array to represent a string for use with %s.
6. main should return an int
7. You don't need stdlib for your current implementation.

No, it's not suppose to check if anything is a palindrome. It's only suppose to generate a palindrome out of the 5 letters that you type in.

One more thing, don't try to assign something the result of printf, it doesn't give you what you want. You probably want something like sprintf instead. Read the docs for printf and sprintf to find out the details of what they do and what they return.