The one that was previously posted on here does not compile or function as intended. Change struct to class Make all the members private Add get_size , get_capacity and get_array methods Add remove, index_of and operator+ methods Add oprator< method, and together with other five ( > , >= , <= , == , != ) Complete and debug all the other methods in the sample code, such as insert Write some testing code in the main function Code template: #include <iostream> using namespace std; struct Vec { int _size; int _cap; int* arr; Vec() { _size = 0; _cap = 4; arr = new int[_cap]; } void insert( int n, int x ) { for ( int i = _size-1; i >= n; i-- ) { arr[i+1] = arr[i]; } arr[n] = x; _size++; } void reserve( int new_cap ) { if ( new_cap > _cap ) { _cap = new_cap; int *tmp = new int[_cap]; for ( int i = 0; i < _size; i++ ) { tmp[i] = arr[i]; } delete[] arr; arr = tmp; } } void push_back( int x ) { if ( _size == _cap ) { _cap *= 2; reserve(_cap); } arr[_size++] = x; } void pop() { if (_size > 0) _size--; } int& at( int idx ) { if ( idx >= _size || idx < 0 ) { throw "[Vector] Index out of bound!"; } return arr[idx]; } int& operator[]( int idx ) { if ( idx >= _size || idx < 0 ) { throw "[Vector] Index out of bound!"; } return arr[idx]; } ~Vec() { delete[] arr; } }; ostream& operator<<(ostream& os, Vec& v) { os << "[ "; for ( int i = 0; i < v._size-1; i++ ) { os << v.arr[i] << ", "; } os << v.arr[v._size-1] << " ]"; return os; } int main() { Vec v; v.push_back(3); v.push_back(1); v.push_back(4); v.push_back(2); v.push_back(8); //v.insert(1, 7); v[3] = 5; cout << v[3] << endl; //v.at(3) = 5; cout << v << endl; //cout << v._cap << endl; //v.reserve(20); //cout << v._cap << endl; //cout << v << endl; //cout << v._size << endl; //cout << v._cap << endl; return 0; } .

1. The one that was previously posted on here does not compile or function as intended.
Change struct to class
Make all the members private
Add get_size , get_capacity and get_array methods
Add remove, index_of and operator+ methods
Add oprator< method, and together with other five ( > , >= , <= , == , != )
Complete and debug all the other methods in the sample code, such as insert
Write some testing code in the main function
Code template:
#include <iostream>
using namespace std;
struct Vec
{
int _size;
int _cap;
int* arr;
Vec()
{
_size = 0;
_cap = 4;
arr = new int[_cap];
}
void insert( int n, int x )
{
for ( int i = _size-1; i >= n; i-- )
{
arr[i+1] = arr[i];
}
arr[n] = x;
_size++;
}
void reserve( int new_cap )
{

2. if ( new_cap > _cap )
{
_cap = new_cap;
int *tmp = new int[_cap];
for ( int i = 0; i < _size; i++ )
{
tmp[i] = arr[i];
}
delete[] arr;
arr = tmp;
}
}
void push_back( int x )
{
if ( _size == _cap )
{
_cap *= 2;
reserve(_cap);
}
arr[_size++] = x;
}
void pop() {
if (_size > 0) _size--;
}
int& at( int idx )
{
if ( idx >= _size || idx < 0 )
{
throw "[Vector] Index out of bound!";
}
return arr[idx];
}
int& operator[]( int idx )
{
if ( idx >= _size || idx < 0 )
{
throw "[Vector] Index out of bound!";
}
return arr[idx];
}

3. ~Vec()
{
delete[] arr;
}
};
ostream& operator<<(ostream& os, Vec& v)
{
os << "[ ";
for ( int i = 0; i < v._size-1; i++ )
{
os << v.arr[i] << ", ";
}
os << v.arr[v._size-1] << " ]";
return os;
}
int main()
{
Vec v;
v.push_back(3);
v.push_back(1);
v.push_back(4);
v.push_back(2);
v.push_back(8);
//v.insert(1, 7);
v[3] = 5;
cout << v[3] << endl;
//v.at(3) = 5;
cout << v << endl;
//cout << v._cap << endl;
//v.reserve(20);
//cout << v._cap << endl;
//cout << v << endl;
//cout << v._size << endl;
//cout << v._cap << endl;
return 0;
}