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

#ifndef DEBUG
#define DEBUG(...) printf(__VA_ARGS__)
#endif

typedef struct Node{
    struct Node *next;
    int val;
} node;

int push(node **top, int val) {
    if(!*top){
        *top=(node *)malloc(sizeof(node));
        if(*top==NULL) return -1;
        (*top)->val=val;
        (*top)->next=NULL;
        return 0;
    }
    node *novi=(node *)malloc(sizeof(node));
    if(novi==NULL){ return -1;}
    novi->val=val;
    novi->next=*top;
    *top=novi;


    return 0;
}

int pop(node **top) {
    if(!*top) return -1;
    node *temp=(node *)malloc(sizeof(node));
    temp=*top;
    *top=(*top)->next;
    free(temp);
    return 0;
}

int print(node *top) {
    if(top==NULL) return -1;
    printf("Stoga: ");
    for(; top!=NULL; top=top->next){
        printf("%d ", top->val);
    }
    printf("\n");
    return 0;
}

int main() {
    node *top = NULL;
    char menu_choice;
    int val, retval;

    do {
        DEBUG("\n(d) dodaj - push\n(b) brisi - pop\n(i) ispis - print\n(e) Exit\n");

        scanf(" %c", &menu_choice);
        switch (menu_choice) {
            case 'd':
                scanf("%d", &val);
                retval = push(&top, val);
                if (retval==-1) printf("Alokacija nije uspjela.\n");
                break;
            case 'b':
                retval = pop(&top);
                if (retval==-1) printf("Stog je prazan.\n");
                break;
            case 'i':
                retval = print(top);
                if (retval==-1) printf("Stog je prazan.\n");
                break;
        }
    } while(menu_choice!='e');

    return 0;
}