Dynamic stack implementation - School HW

dynamic_stack.c

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

struct node {
    int data;
    struct node *next;
};

struct stack {
    struct node *head;
    int size;
};

void init(struct stack *structstack) {
    structstack->head = 0;
    structstack->size = 0;
}

void push(struct stack *structstack, int value) {
    struct node *_new = malloc(sizeof *_new);
    _new->data = value;
    _new->next = structstack->head;
    structstack->head = _new;
    structstack->size++;
}

int pop(struct stack *structstack, int *el) {
    if (structstack->size <= 0)
        return 0;
    *el = structstack->head->data;
    struct node *topop = structstack->head;
    structstack->head = structstack->head->next;
    free(topop);
    structstack->size--;
    return 1;
}

void show_stack(struct stack *structstack) {
    struct node *n = structstack->head;
    while (n) {
        printf("%d ", n->data);
        n = n->next;
    }
}

int main(int argc, char *argv[]) {
    struct stack _stack;
    init(&_stack);
    for (int i = 1; i < argc; ++i) {
        push(&_stack, atoi(argv[i]));
        printf("Pushed %d to the stack.\n", atoi(argv[i]));
    }

    int el;
    for (int i = 0; i < argc; ++i) {
        if (pop(&_stack, &el))
            printf("Popped %d from stack.\n", el);
        else
            printf("Stack empty.\n");
    }
    show_stack(&_stack);
    return 0;
}