#include <iostream>
#include <cstdlib>
#include <vector>
using namespace std;

int main()
{
	const int a[] = {10, 21, 30};
	const size_t n = sizeof a / sizeof a[0];
	vector<int> v(a, a + n);

	cout << "size == " << v.size() << ", capacity == " << v.capacity() << "\n";
	vector<int>::iterator it = v.begin() + 1;   //Refer to the 21.
	*it = 20;                                   //Overwrite the 21.
	cout << "size == " << v.size() << ", capacity == " << v.capacity() << "\n";

	for (it = v.begin(); it != v.end(); ++it) {
		cout << *it << "\n";
	}

	return EXIT_SUCCESS;
}