Question

Write a program that determines whether an input string is a palindrome; that is, whether it can be read the same way forward and backward. At each point, you can read only one character of the input string; do not use an array to first store this string and then analyze it (except, possibly, in a stack implementation). Consider using multiple stacks.

In Pseudocode please

Answer 1

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

char* stack;
int top = -1;

//Push function

void push (char ele){ 
   stack [++top] = ele;
}

//Pop function
char pop() {
  return stack [top--];
}

//Function that returns 1 
//If str is a palindrome
int isPalindrome (char str[]) {
  int length = strlen(str);

//Allocating the memory for the stack
  stack= (char*)malloc(length * size of(char));

//Finding the mid
  int i,mid = length/2;
  for(i=0;i<mid;i++) {
  push(str[i]);

//Checking if the length of the string 
// is odd, if odd then neglect the
//middle character
  if(length % 2 != 0) {
  i++;
}

/)While not the end of the string
while(str[I] != '\0') {
char ele = pop();

//If the character differ then the 
//given string is not a palindrome
if (ele != str[i])
 return 0;
  i++;
}
  return 1;

//Driver code

main ()
char str[] = "madam";
 if(isPalindrome (str)) {
print("Yes");
}
else {
 print("No");
}return 0;
}


Output:- Yes