Stek (stack)

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

#define STACK_NULL -1

typedef int nodeType;

typedef struct nodeStackStruct {
    struct nodeStackStruct *next;
    nodeType data;
} nodeStack;


void push(nodeStack **top, nodeType data) {
    nodeStack *new;

    new = (nodeStack *)malloc(sizeof(nodeStack));
    new->data = data;
    new->next = *top;
    *top = new;
}

nodeType pop(nodeStack **top) {
    nodeType data;
    nodeStack *tmp;

    if (*top == NULL)
        return STACK_NULL;

    data = (*top)->data;
    tmp = *top;
    *top = tmp->next;
    free(tmp);

    return data;
}

nodeType top(nodeStack *top) {
    if (top == NULL)
        return STACK_NULL;

    return top->data;
}

nodeType deleteStack(nodeStack *top) {
    if (top != NULL) {
        deleteStack(top->next);
        free(top);
    }
}

void printStack(nodeStack *top) {
    if (top != NULL) {
        printf("%d\n", top->data);
        printStack(top->next);
    }
}

int main() {
    nodeStack *top;
    top = NULL;

    push(&top, 10);
    push(&top, 20);

    printStack(top);

    deleteStack(top);

    return 0;
}