SYBCom(CA) DS Practical Slip 8 Q.A

Write a ‘C’ program which accepts the string and check whether the string is Palindrome or not using stack. (Use Static / Dynamic implementation of Stack).

#include <stdio.h>
#include <string.h>
#define MAX 100

// Stack implementation using array
char stack[MAX];
int top = -1;

// Push function
void push(char ch) {
    if (top == MAX - 1) {
        printf("Stack Overflow\n");
        return;
    }
    stack[++top] = ch;
}

// Pop function
char pop() {
    if (top == -1) {
        printf("Stack Underflow\n");
        return '\0';
    }
    return stack[top--];
}

int main() {
    char str[MAX];
    int len, i, flag = 1;

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

    len = strlen(str);

    // Push all characters of the string into stack
    for(i = 0; i < len; i++) {
        push(str[i]);
    }

    // Pop characters and compare with original string
    for(i = 0; i < len; i++) {
        if(str[i] != pop()) {
            flag = 0;
            break;
        }
    }

    if(flag)
        printf("The string \"%s\" is a palindrome.\n", str);
    else
        printf("The string \"%s\" is NOT a palindrome.\n", str);

    return 0;
}