// 使用STL双端队列类
#include <deque>
#include <iostream>
#include <algorithm>

int main() {
	using namespace std;

	// Define a deque of integers
	deque<int> dqIntegers;

	// Insert integers at the bottom of the array
	dqIntegers.push_back(3);
	dqIntegers.push_back(4);
	dqIntegers.push_back(5);

	// Insert integers at the top of the array
	dqIntegers.push_front(2);
	dqIntegers.push_front(1);
	dqIntegers.push_front(0);

	cout << "The contents of the deque after inserting elements ";
	cout << "at the top and bottom are:" << endl;

	// Display contents on the screen
	for (size_t nCount = 0; nCount < dqIntegers.size(); ++nCount) {
		cout << "Element [" << nCount << "] = ";
		cout << dqIntegers[nCount] << endl;
	}

	cout << endl;

	// Erase an element at the top
	dqIntegers.pop_front();

	// Erase an element at the bottom
	dqIntegers.pop_back();

	cout << "The contents of the deque after erasing an element ";
	cout << "from the top and bottom are:" << endl;

	// Display contents again: this time using iterators
	deque<int>::iterator iElementLocator;
	for (iElementLocator = dqIntegers.begin()
	; iElementLocator != dqIntegers.end(); ++iElementLocator) {
		size_t nOffset = distance(dqIntegers.begin(), iElementLocator);
		cout << "Element [" << nOffset << "] = " << *iElementLocator << endl;
	}

	return 0;
}