Stack Implementation Using Structure.c

#include <stdio.h>

#define MAX 100

/* Stack structure */
struct Stack
{
    int data[MAX];
    int top;
    int size;
};

/* Function declarations */
void push(struct Stack *s);
void pop(struct Stack *s);
void show(struct Stack s);

int main(void)
{
    struct Stack s;
    int choice = 0;

    s.top = -1;

    printf("Enter the number of elements in the stack: ");
    scanf("%d", &s.size);

    if (s.size > MAX)
    {
        printf("Stack size exceeds maximum limit (%d)\n", MAX);
        return 0;
    }

    printf("\n********* Stack Operations Using Structure *********\n");

    while (choice != 4)
    {
        printf("\nChoose one from the below options...");
        printf("\n1. Push\n2. Pop\n3. Show\n4. Exit");
        printf("\nEnter your choice: ");
        scanf("%d", &choice);

        switch (choice)
        {
            case 1:
                push(&s);
                break;

            case 2:
                pop(&s);
                break;

            case 3:
                show(s);
                break;

            case 4:
                printf("Exiting...\n");
                break;

            default:
                printf("Please enter a valid choice!\n");
        }
    }

    return 0;
}

void push(struct Stack *s)
{
    int val;

    if (s->top == s->size - 1)
    {
        printf("Stack Overflow!\n");
    }
    else
    {
        printf("Enter the value to push: ");
        scanf("%d", &val);
        s->top++;
        s->data[s->top] = val;
        printf("%d pushed into stack\n", val);
    }
}

void pop(struct Stack *s)
{
    if (s->top == -1)
    {
        printf("Stack Underflow!\n");
    }
    else
    {
        printf("Popped element: %d\n", s->data[s->top]);
        s->top--;
    }
}

void show(struct Stack s)
{
    if (s.top == -1)
    {
        printf("Stack is empty\n");
    }
    else
    {
        printf("Stack elements are:\n");
        for (int i = s.top; i >= 0; i--)
        {
            printf("%d\n", s.data[i]);
        }
    }
}