Palindrome

hi everybody

question: Can anyone help me out to make a program that checks a string for being a palindrome or not

I only want to get the logic, so that I could try it myself

thanx in advance

bye

> I only want to get the logic, so that I could try it myself
Compare the first letter with the last letter

If they match, move in one letter from each end and repeat

If you meet in the middle, and its still equal, its a palindrome

If you really want to be masochistic, you can push all the letters in a stack pop them all off into a new stirng and then use strcmp. If its == 0, its a palindrome

Here's one way of doing it.....

Extra brownie points if you understand it...... lol
This was written by richard heathfield,one of the authors of c unleashed.... enjoy....

Code:

#include <stdio.h>
#include <string.h>
#include <ctype.h>

#define p void
#define   a sizeof
#define      l char
#define        i return
#define          n int
#define           d size_t
#define            r if
#define             o while
#define              m else
#define              e for
#define              ob putchar
#define              fu strlen
#define             sc isalpha
#define             at tolower
#define            ed fgets
#define          cp printf
#define        ro strchr
#define     gr main
#define am stdin
n c(l*s){n k=
0;r(s){d x
=fu (s)
;r(x>1)
{l*t=s,
*u=s+x-
1;k=1;o
(k&&t<u
){r(sc(
*t)){r(
sc(*u))

    {r(at(
   *t)!=at(
  *u)    ){k
 =0;      }m{
++t;--u;}}m{--
u;}}m{++t;}}}}
i k        ;}n
gr(        p){
l b        [01
<<1        <<1

<<1
<<1
<<1
<<1
<<1
<<1
<<1
],*
z,*s=" adeil"
"mnoprst.\n";

n f[]={00,01<<1
<<1,(1<<1<<1<<1
      )|(
      1<<
      1)|
      1},
      v[]
      ={0
,(1<<1<<1)|(1<<
1)|1,1<<1<<1<<1


,(1         <<1
<<01        <<1
)|(01       <<1
<<1 )}      ,q[
]={  (1     <<1
)&1   ,1    <<1
>>1    ,1   >>1
,(1     <<  1<<
1<<      1) |1,
1<<       01<<1


>>1>>1,(1<<1
<<1       )|(
1<<        1>>
1),         1<<
1<<         1,(
1<<         1<<
1)|         (01
<<1        )|1
,01       <<1
,(1<<1<<1<<1


)|(1<<01),1
<<1      <<1
<<1       ,(1
<<1       <<1
)|1      <<1
,(1   <<1
)|1,(1<<
1<<   1<<
1)|    (01
<<1     <<1
)|1      ,(1
<<1       <<1


   <<1)|(1<<
 1<<       1)|
(01         <<1
)};         d y
;o(         ed(
b,a         (b)
,am         )){
{z=         ro(
 b,1        *1*
   '\n');}if(

z){          *z=
00;}        {cp(
"%s",      b);}e
(y=0;1    *y<a f
/a( 1[f  ]); y++
)ob  (y[f][  s])
;r(   !c(b   ))e
(y=    0;    y<a
v/a          1[v
];y          ++)


ob(01*y[v][s]);e
(y=0/1*1/1<<1<<1
<<1
;y<
a q
/a 1[q]
;y++)ob
(y[
q][
s])
;}i 0>>1<<0>>1<<
1*1/(1<<1<<01);}

Gee, does that code really work? I'll have to try when I get home

PS: What does obfuscated mean?

That code Stoned Coder posted is the very definition of obfuscated (to make so difficult/confusing its hard to understand).

And those define's aren't kidding!