Lecture18code-vecstring.txt

/*
 *  File: myvector.h
 *  ----------------
 *
 *  Created by Julie Zelenski on 2/22/08.
 *
 */
#ifndef _myvector_h
#define _myvector_h

#include "genlib.h"

class MyVector
{
 public:
	MyVector();
	~MyVector();
	
	int size();
	void add(string s);
	string getAt(int index);
	
  private:
	string *arr;
	int numUsed, numAllocated;
	void doubleCapacity();

};


#endif

/*
 *  File: myvector.cpp
 *  ------------------
 *
 *  Created by Julie Zelenski on 2/22/08.
 *
 */

#include "myvector.h"

MyVector::MyVector()
{	
	arr = new string[2];
	numAllocated = 2;
	numUsed = 0;
}

MyVector::~MyVector()
{
	delete[] arr;
}


int MyVector::size()
{
	return numUsed;
}

string MyVector::getAt(int index)
{
	if (index < 0 || index >= size())
		Error("Out of bounds");
	return arr[index];
}

void MyVector::add(string s)
{
	if (numUsed == numAllocated)
		doubleCapacity();
	arr[numUsed++] = s;
}

void MyVector::doubleCapacity()
{
	string *bigger = new string[numAllocated*2];
	for (int i = 0; i < numUsed; i++)
		bigger[i] = arr[i];
	delete[] arr;
	arr = bigger;
	numAllocated*= 2;
}