Queue & Stack in cpp

queue.cpp

#include <iostream>
using namespace std;

const int maxElmt = 10;

struct Queue {
  int data[maxElmt];
  int head;
  int tail;
};

// create queue
// init head & tail as -1
// -1 means, the array is empty
void createQueue(Queue &q) {
  q.head = -1;
  q.tail = -1;
}

void push(Queue &q, int elm) {
  // kalau queue kosong
  if (q.tail == -1) {
    // data pertama
    q.head = 0;
    q.data[0] = elm;
    q.tail = 0;

    cout << "data99: " << q.data[0] << endl;

    // terminate current function
    return;
  }

  // kalau queue udah penuh
  if (q.tail == maxElmt-1) {
    cout << "puntent, udah penuh" << endl;
    // terminate current function
    return;
  }

  // kalau queue berisi
  q.tail++;
  q.data[q.tail] = elm;
}

void print(Queue q) {
  // print queue
  cout << "queue: ";
  if (q.tail < 0) {
    cout << "queue kosong" << endl;
    return;
  }

  for (int i = 0; i <= q.tail; i++) {
    cout << q.data[i] << " ";
  }
}

int main() {
  Queue queue;

  createQueue(queue);
  // mock
  for (int i = 0; i < maxElmt; i++) {
    push(queue, i);
  }

  push(queue, 9999);
  print(queue);
}

stack.cpp

// Program stack
// 

#include <iostream>
using namespace std;

const int maxElm = 10;

struct Stack {
  int isi[maxElm];
  int top;
};

// inisiasi stack kosong
void createStack(Stack &s) {
  // -1 berati stack kosong
  // top itu menunjukkan index dari Stack
  // stack mulai 0 - maxElm
  s.top = -1;
}

// push element into stack start from bottom of stack
// the top var will be increment
void push(Stack &s, int elm) {
  // we check if stack is full
  // top is zero-indexed
  bool isStackFull = s.top == maxElm-1;
  if (isStackFull) {
    cout << "maaf geus pinuh" << endl;
    // terminate current function
    return;
  }

  // increment top, cuz top is -1 in the first place
  // kalau stack kosong, s.top = -1; 
  // ketika dipush, s.top++ maka s.top = 0;
  s.top++;
  s.isi[s.top] = elm;
}

int main () {
  Stack s;

  cout << "Init stack " << s.top;
  createStack(s);
  cout << "top: " << s.top << endl;

  cout << "push 99 " << endl;
  push(s, 99);

  cout << "after push" << endl;
  cout << "top: " << s.top << endl;
  cout << "top elemt: " << s.isi[s.top] << endl;
}