Problem with the palindrome

[a_learner]

hi
can anyone help me out of this program


/*program to determine a palindrome*/
#include<stdio.h>
#include<conio.h>
#include<string.h>

int main()
{
int check(char *start);
char word[40];
int result;

printf("\nEnter the string\t");
scanf("%s",word);

result=check(word);

if(result==1)
printf("\n%s is a palindrome\n",word);
else
printf("\n%s is not a palindrome\n",word);


getche();
return 0;
}

int check(char *start)
{
char *end;
int i,len=0;

while(*start!='\0')
{
len++;
*start++;
}
start=start-len;
end=start+len;

for(i=0;i<len/2;i++)
{
if(*start==*end)
{
*start++;
*end--;
return 1;
}
else
return 0;
}
}

[GaPe]

You complicated this program too much.

Use this...

int Palindrome(char String[100])
{
int counter1=0, counter2=0, counter3=0;

counter2 = strlen(String);
for (counter1=0;counter1<=strlen(String); counter1--)
{
counter2--;
if (String[counter1] == String[counter2])
{
counter3 = 1;
}
}
return counter3;
}

It's easy. The string is read from the beginning to the end and reverse.

[Prelude]

Use this as a template for your program. Since this is only one solution, see if you can come up with another.

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

int main(void){
	char string[1024];
	int tag, count, back, flag, loop = 1;

	while(loop == 1){
		flag = 1;

		puts("Enter a word, phrase, or sentence. Or type 'END' to exit:");
		for(count = 0; (string[count = getchar()) != '\n'; ++count)
			;
		if((toupper(string[0]) == 'E') && (toupper(string[1]) == 'N') &&
			(toupper(string[2]) == 'D'))
			break;
		tag = count - 1;

		for((count = 0, back = tag); count <= tag/2; (++count, --back)){
			if(string[count] != string[back]){
				flag = 0;
				break;
			}
		}

		for(count = 0; count <= tag; ++count)
			putchar(string[count]);
		if(flag == 1)
			puts(" is a palindrome\n");
		else
			puts(" is not a palindrome\n");
	}
}

-Prelude

[Garfield]

>> if((toupper(string[0]) == 'E') && (toupper(string[1]) == 'N') &&
(toupper(string[2]) == 'D'))
<<

Optimized:

strupr(string);

if (!strcmp("END", string))
/*** ETC ***/

[mattz]

strupr(string);

if (!strcmp("END", string))
/*** ETC ***/



Does not seem to work...FYI

Mattz

[Garfield]

Let me see all of your code. Don't forget to use the code tags to make it readable.

[mattz]

Here is my first attempt. Modified it a bit and it seems to work..but noticed its probably not in the right place as it should print out the contents of buffer when I type QUIT instead of just abruptly ending.
<code>
#include <stdio.h>
#include <string.h>

int main()
{

/* A struct is used to define the character
array */

struct str_array{
char buffer[50];
};



int i; /* to be used as an index */

char in_val[50]; /* used within gets() */

struct str_array buf[10]; /* an array of
struct str_array

buf[0] .. buf[9] */

/* as a demo, prompts for seven strings are
provided */



for (i=0; i<=6; i++)
{

printf("Enter a string -> ");
fflush(stdin); /* definitely, for gets() */
gets(in_val); /* input string */

/* syntax of strcpy(a,b) is such that a
is the "destination" and b is the
"source" */

strcpy(buf[i].buffer, in_val); /* note
buf[i].buffer */

/* some light testing is performed */

printf("Just after gets now!\n");
printf("String provided as input was: ");
puts(in_val);

if (strcmp("QUIT", in_val)==0)

return 0;


}

/* contents of the array of structs
provided as output */

for (i=0; i<=6; i++)
{

puts(buf[i].buffer);

}

return 0;

}
</code>

[Unregistered]

This should help:

#include<stdio.h>
#include<stdlib.h>
int main()
{
char string1[20];
puts("Enter string one.");
gets(string1);
char string2[20];
string2=strrev(string1);
if (strcmp(string1,string2)==0)
{
puts("Palindrome.");
}
else
{
puts("Not a palindrome.");
}
return 0;
}
Just an idea for a syntax. Cya.

[quzah]

char string2[20];
string2=strrev(string1);

No. This is incorrect. You cannot use an array to handle a char* return value like this. 'string2' must be a 'char*'.

Quzah.

[mattz]

QUZAH,
Any ideas on how to fix this program I posted earlier? Want to have the user type "QUIT" to exit and then print out the string arrays.

Mattz

[mattz]

or if they actually fill the 7 arrays that are counted it prints.