c++:vector

#include<iostream>
#include<iomanip>
#include<vector>
using namespace std;
int main(){
	vector<int> A(10);
	int n;
	int primecount = 0, i, j;
	cout << "enter a value>=2 as upper limit for prime numbers;";
	cin >> n;
	A[primecount++] = 2;
	for (i = 3; i < n; i++){
		if (primecount == A.size())
			A.resize(primecount + 10);
		if (i % 2 == 0)
			continue;
		j = 3;
		while (j <= i / 2 && i%j != 0)
			j += 2;
		if (j>i / 2)
			A[primecount++] = i;
	}
	for (i = 0; i < primecount; i++){
		cout << setw(5) << A[i];
		if ((i + 1) % 10 == 0)
			cout << endl;
	}
	cout << endl;
}

#include<iostream>
#include<deque>
#include<algorithm>
#include<iterator>
using namespace std;
int main(){
	deque<double>values;
	ostream_iterator<double>  output(cout, " ");
	values.push_front(2.2);
	values.push_front(3.3);
	values.push_back(1.1);
	cout << "values contains:";
	for (int i = 0; i < values.size(); i++)
		cout << values[i] << ' ';
	values.pop_front();
	cout << "
 after pop_front values contains:";
	copy(values.begin(), values.end(), output);
	values[1] = 5.5;
	cout << "
 after values[1]=5.5 values contains:";
	copy(values.begin(), values.end(), output);
	cout << endl;
}

#include<iostream>
#include<vector>
#include<algorithm>
#include<iterator>
using namespace std;
int main(){
	int A[] = { 1, 2, 3, 4, 5 };
	const int N = sizeof(A) / sizeof(int);
	vector<int>coll(A, A + N);
	ostream_iterator<int> output(cout, " ");
	cout << "list coll contains:";
	copy(coll.begin(), coll.end(), output);
	vector<int>::iterator pos = coll.begin();
	cout << "
 the first element is:" << *pos;
	vector<int>::reverse_iterator rpos = coll.rbegin();
	cout << "
 the last element is:" << *rpos << endl;
	back_insert_iterator<vector<int>> iter(coll);
	*iter = 66;
	back_inserter(coll) = 88;
	copy(coll.begin(), coll.end(), output);
	cout << endl;
}

#include<iostream>
#include<numeric>
using namespace std;
int mult(int x, int y){ return x*y; };
int main(){
	int a[]={1, 2, 3, 4, 5};
	const int n = sizeof(a) / sizeof(int);
	cout << "the result by multipling all elements in a is:" << accumulate(a, a + n, 1, mult) << endl;
}