#include <stdio.h>

#define STACK_SIZE 100

int stack[STACK_SIZE];
int sp = 0;

void push(int x) {
    stack[sp++] = x;
}

int pop() {
    return stack[--sp];
}

int main() {
    int data[] = {11, 12, 13, 14, 15};
    int n = 5;

    printf("data[] = ");
    for(int i = 0; i < n; i++) {
        printf("%d ", data[i]);
    }
    printf("\n");

    printf("push & pop\n");

    /* push */
    for(int i = 0; i < n; i++) {
        push(data[i]);
    }

    for(int i = 0; i < n; i++) {
        data[i] = pop();
    }
    printf("data[] = ");
    for(int i = 0; i < n; i++) {
        printf("%d ", data[i]);
    }
    printf("\n");

    return 0;
}