Stack.c

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

struct stack
{
char *a;
int size;
int top;
};

int isempty(struct stack *st)
{
return st->top == -1;
}

void push(struct stack *st, char c)
{
st->top++;
st->a[st->top] = c;
}
char pop(struct stack *st)
{
char c = st->a[st->top];
st->top--;
return c;
}

int palindrome(char str[])
{

struct stack *st = (struct stack *)malloc(sizeof(struct stack));
st->a = (char *)malloc(100 * (sizeof(char)));
st->size = 100;
st->top = -1;

int i;
for ( i = 0; str[i] != '\0'; i++)
push(st, str[i]);

while (!isempty(st))
{
char c = pop(st);
if (c == str[i])
i++;
else
return 0;
}
return 1;
}

int main()
{
char str[100];

printf("Enter the string:");
scanf("%s", str);

if (palindrome(str))

printf("The given string is a palindrome!\n");
else
printf("The given string is not a palindrome!\n");
}