#include "stdstuff.h"

#include "IAStack.h"

static const int initialCapacity = 10,
                 capacityIncrement = 5;


IntArrayStack::IntArrayStack () {

  data = new int [initialCapacity];
  capacity = initialCapacity; elastic = true;
  count = 0;

}


IntArrayStack::IntArrayStack (int capacity) {

  if (capacity <= 0) {
    throw invalid_argument ("IntArrayStack::IntArrayStack - invalid capacity");
  }

  data = new int [capacity];
  this -> capacity = capacity; elastic = false;
  count = 0;

}


IntArrayStack::IntArrayStack (const IntArrayStack &otherStack) {

  data = new int [otherStack.capacity];
  capacity = otherStack.capacity;
  elastic = otherStack.elastic;
  count = otherStack.count;
  
  for (int i = 0; i < count; i++) {
    data[i] = otherStack.data[i];
  }

}


IntArrayStack::~IntArrayStack () {

  delete [] data;

}


void IntArrayStack::push (int value) {

  int *temp, i;

  if (elastic && (count == capacity)) {
    // time to increase the capacity
    capacity += capacityIncrement;
    temp = new int [capacity];
    for (i = 0; i < count; i++) temp[i] = data[i];
    delete [] data;
    data = temp;
  } else if (count == capacity) {
    throw overflow_error ("IntArrayStack::push - stack overflow");
  }

  data[count++] = value;

}


int IntArrayStack::pop () {

  if (count == 0) {
    throw overflow_error ("IntArrayStack::pop - stack underflow");
  }

  return data[--count];

}


IntArrayStack& IntArrayStack::operator= (const IntArrayStack &otherStack) {

  if (capacity < otherStack.count) {
    if (!elastic) {
      throw overflow_error ("IntArrayStack - copy overflow");
    }
    delete [] data;
    data = new int[otherStack.count];
    capacity = otherStack.count;
  }
  for (int i = 0; i < otherStack.count; i++) {
    data[i] = otherStack.data[i];
  }
  count = otherStack.count;
  return *this;

}