// Simple stack of integer values with usual push, pop, and check
// for emptiness. If an empty stack is popped, you just get 0 back.

#include "istack.h"

//  Testing interface - get values from command line, push, display, pop
int main(int argc, char *argv[]) {
    if (argc < 2) {
        fprintf(stderr,"Usage: %s n1 n2 ... nk\n", argv[0]);
        return -1;
    }

    StackItem stack;
    stackInitialize(&stack);
    for (int i = 1; i < argc; ++i) {
        push(&stack, atoi(argv[i]));
    }
    stackDisplay(&stack);


    printf("pop returns %d\n", pop(&stack));
    printf("pop returns %d\n", pop(&stack));
    printf("After 2 pops, the stack is\n");
    stackDisplay(&stack);

    while (!stackIsEmpty(&stack)) {
        printf("popped %d ...", pop(&stack));
    }
    printf("\n");

    printf("Now the stack is\n");
    stackDisplay(&stack);
}