#include <iostream>
#include <vector>
using namespace std;
 
class X : public vector<int> { };
 
void show(const X& e)
{
	size_t n = e.size();
	for (size_t i=0; i<n; i++) {
		cout << " [" << i << "] = " << e[i] << "\n";
	}
	cout << "\n";
}
 
void show(const X& e1, const X& e2, const vector<X>& list)
{
	cout << "--------------\n";
	cout << "e1:" << e1.size() << "\n";
	show(e1);
 
	cout << "e2:" << e2.size() << "\n";
	show(e2);
 
	size_t n = list.size();
	for (size_t i=0; i<n; i++) {
		cout << "list[" << i << "]:" << list[i].size() << "\n";
		show(list[i]);
	}
}
 
int main() {
	X e1, e2;
	vector<X> list;
 
	cout << "(1)初期状態\n";
	e1.push_back(0);
	e2.push_back(1);
	e2.push_back(2);
	list.push_back(e1);
	list.push_back(e2);
	show(e1, e2, list);
 
	cout << "(2)呼び出し元の実体を拡大\n";
	e1.push_back(3);
	e2.push_back(4);
	show(e1, e2, list);
 
	cout << "(3)vector の要素を拡大\n";
	list[0].push_back(5);
	list[1].push_back(6);
	show(e1, e2, list);
 
	return 0;
}

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