stacks in c

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

#define MAX_SIZE 10

struct Stack {
    int arr[MAX_SIZE];
    int top;
};

void initialize(struct Stack *s) {
    s->top = -1;
}

int isEmpty(struct Stack *s) {
    return (s->top == -1);
}

int isFull(struct Stack *s) {
    return (s->top == MAX_SIZE - 1);
}

void push(struct Stack *s, int value) {
    if (isFull(s)) {
        printf("Stack overflow\n");
        return;
    }
    s->arr[++s->top] = value;
}

int pop(struct Stack *s) {
    if (isEmpty(s)) {
        printf("Stack underflow\n");
        exit(1);
    }
    return s->arr[s->top--];
}

int peek(struct Stack *s) {
    if (isEmpty(s)) {
        printf("Stack is empty\n");
        exit(1);
    }
    return s->arr[s->top];
}

int main() {
    struct Stack stack;
    initialize(&stack);

    push(&stack, 10);
    push(&stack, 20);
    push(&stack, 30);

    printf("Top element: %d\n", peek(&stack));
    printf("Popped element: %d\n", pop(&stack));
    printf("Top element after pop: %d\n", peek(&stack));

    return 0;
}