QUES 22 PALINDROME

C LANGUAGE BOOK

suppose u enter a string s1 say
eve
 the reverse of eve s2 is
 eve
hence s1 and s2 are equal
the string eve is palindrome.



suppose u enter a number n1 say
121

 the reverse of number n2 is

 121
hence n1 and n2 are equal
the number 121 is palindrome.

/*
WAP TO CHECK WHETHER A STRING ENTERED BY
THE USER.IS PALINDROME OR NOT.
*/

#include<stdio.h>
#include<conio.h>
void main()
{
  int xstrlen(char *);
 
  char a[30],b[30];

int n,len,i;

  clrscr(); //CLEARS THE OUTPUT SCREEN

/*Check String Palindrome*/

  printf("Enter the String to Check for Palindrome: ");
  gets(a); //TAKING THE STRING
  len= strlen (a);
  printf("\n the string is");
  printf("\t%s" ,a); //PRINT THE ENTERED STRING


  xstrcpy(a,b);//copy source string a into target string b
  xstrrev(b);
  printf("\t%s" ,b); //PRINT THE REVERSED STRING
  i=xstrcmp(a,b);

if(i==0)
  printf("String is a Palindrome ");
else
  printf("String is not a Palindrome ");

/*Check Number Palindrome*/


  printf("Enter the Number to Check for Palindrome: ");
  scanf("%d",&n); //TAKING THE NUMBER
 
xnopal(n);
  getch();
}

void xstrcpy(char *s,char *t)
{

while(*s!='\0')
 {
*t=*s;
s++;
t++;
}

}

void xstrrev(char *s) 

{
     int length, c;
     char *begin, *end, temp;
     
     length = strlen(s);

     begin = s;
     end = s;
     
     for ( c = 0 ; c < ( length - 1 ) ; c++ )
         end++;
          
     for ( c = 0 ; c < length/2 ; c++ ) 
     {        
         temp = *end;
         *end = *begin;
         *begin = temp;
         
         begin++;
         end--;
     }
}

int xstrcmp(char *s,char *t)
{
int length;

length = strlen(s);

/*Comparing String*/

while(length>0)
 {
        if((*s)==(*t))
       {
         s++;
         t++;
        }
        else
       {    return -1; }
 }
 return 0;
}



 
void xnopal(int n)
{

int temp,remainder,rev=0;

 temp=n;
while(n>0)
{
remainder=temp%10; //Gets Last Digit
 temp=temp/10;  //Truncates Last Digit
rev=rev*0+remainder;  //Builds reversed number
}
printf("\n%d" ,n); //PRINT THE ENTERED NUMBER
printf("\n%d" ,rev); //PRINT THE REVERSED NUMBER
if(rev==n)

printf ("\nThe Number Is A Palindrome ");

else

printf ("\nThe Number Is Not A Palindrome ");

 }

C LANGUAGE BOOK