Answer to Question #27332 in C++ for shahzad

Question

Implement array-based list for integers; following methods should be implemented. Dynamic array would be preferred.
void insertAtPosition(int x,int pos); //insert value x at given position
void insertAtEnd(int x); //insert value at the end of the array
void insertAtFront(int x); //insert value at the first position of the array
void removeFromFront(); //remove element from first position and move all element up //to fill the gap
void removeFromEnd(); //remove element from the end of the array
void removeFromPosition(int pos); //remove element from the position given by user. After the //operation there should be no gap in the elements of array
int find(int x) const; //return the index
int findPosition(int pos) const; //find at given position and return the value
bool IsEmpty() const; //return true if list is empty
bool isFull() const; //return true if list is full
void print() const; //print the whole list
Note: Implement the main() to show that all above given methods are working properly

Answer 1

#include <iostream>
using std::cout;
using std::endl;

template<class T>
class CArray {
struct Item {
T value;
};

Item * items;

int size;

int capacity;

public:
CArray() {
capacity = 1;

items = new Item[capacity];

size = 0;
}

CArray(const CArray<T>& a) {
if (this != &a) {
capacity = a.GetSize();

items = new Item[capacity];

size = 0;

for (int i = 0; i < a.GetSize(); i++) {
PushToEnd(a[i]);
}
}
}

virtual ~CArray() {
delete items;
}

CArray& operator=(const CArray& a) {
if (this != &a) {
delete items;

capacity = a.GetSize();

items = new Item[capacity];

size = 0;

for (int i = 0; i < a.GetSize(); i++) {
PushToEnd(a[i]);
}
}
}

void PushToBegin(const T& value) {
if (size == capacity) {
int newCapacity = 2 * capacity;

Item * buffer = new Item[newCapacity];

for (int i = 0; i < size; i++) { buffer[i] = items[i]; }

delete items;

capacity = newCapacity;

items = new Item[capacity];

for (int i = 0; i < capacity; i++) { items[i] = buffer[i]; }

delete buffer;
}

for (int i = size; i >= 0; i--) {
items[i] = items[i - 1];
}

items[0].value = value;

size++;
}

void PushToEnd(const T& value) {
if (size == capacity) {
int newCapacity = 2 * capacity;

Item * buffer = new Item[newCapacity];

for (int i = 0; i < size; i++) { buffer[i] = items[i]; }

delete items;

capacity = newCapacity;

items = new Item[capacity];

for (int i = 0; i < capacity; i++) { items[i] = buffer[i]; }

delete buffer;
}

items[size].value = value;

size++;
}

void RemoveFromBegin() {
if (size > 0) {
for (int i = 0; i < size; i++) {
items[i] = items[i + 1];
}

size--;
}
}

void RemoveFromEnd() {
size--;
}

void Clear() {
size = 0;
}

int GetSize() const {
return size;
}

T operator[](const int index) const {

//if ((size < 0) || (index >= size)) {
// throw IllegalArgumentException("Index must be more then zero.");
//}

return items[index].value;
}
T& operator[](const int index)& {

//if ((size < 0) || (index >= size)) {
// throw IllegalArgumentException("Index must be more then zero.");
//}

return items[index].value;
}
};

template <class T>
std::ostream& operator<<(std::ostream& out, const CArray<T>& a) {
out << "[";
for (int i = 0; i < a.GetSize(); i++) {
out << a[i] << (i == (a.GetSize() - 1) ? "" : ", ");
}
out << "]";
return out;
}