Implement a stack or queue to perform comparison and check for symmetry in C

#include <stdio.h>

#include <string.h>

#define MAX 100

// Stack structure

typedef struct {

    char data[MAX];

    int top;

} Stack;

// Initialize stack

void init(Stack *s) {

    s->top = -1;

}

// Check if stack is empty

int isEmpty(Stack *s) {

    return s->top == -1;

}

// Check if stack is full

int isFull(Stack *s) {

    return s->top == MAX - 1;

}

// Push element to stack

void push(Stack *s, char ch) {

    if (isFull(s)) {

        printf("Stack is full.\n");

        return;

    }

    s->data[++(s->top)] = ch;

}

// Pop element from stack

char pop(Stack *s) {

    if (isEmpty(s)) {

        printf("Stack is empty.\n");

        return '\0';

    }

    return s->data[(s->top)--];

}

// Check symmetry using stack

void checkSymmetry(char str[]) {

    Stack s;

    init(&s);

    

    int len = strlen(str);

    int i;

    

    // Push first half to stack

    for (i = 0; i < len / 2; i++) {

        push(&s, str[i]);

    }

    // If length is odd, skip middle character

    if (len % 2 != 0) {

        i++;

    }

    // Compare second half with stack

    while (str[i] != '\0') {

        char ch = pop(&s);

        if (ch != str[i]) {

            printf("The string '%s' is NOT symmetric.\n", str);

            return;

        }

        i++;

    }

    printf("The string '%s' is symmetric.\n", str);

}

int main() {

    char str1[MAX];

    printf("Enter a string to check symmetry: ");

    scanf("%s", str1);

    checkSymmetry(str1);

    return 0;

}

Output: