4.1.12.1 Partitioning operations

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>

using namespace std;

struct Generate
{
	int s;
	int i;
	Generate() : s(0), i(1) {}
	int operator()()
	{
		s += i;
		return s;
	}
};

void print(const int & value)
{
	cout << value << " ";
}
bool str(const int & a) {

	int n = 0;
	string s = to_string(a);
	char const *pchar = s.c_str();
	for (int i = 0; i < s.length(); i++) {
		if (pchar[i] == '3')
			n++;
	}
	if (n != 0)
		return true;
	else return false;
}

struct Three
{
	int n;
	Three() :n(0) {}
	bool operator()(const int & a)
	{
		return (a % 3 == 0) || (str(a));
	}
};

int main()
{
	vector<int> results(40);

	generate_n(results.begin(), 40, Generate());
	vector<int>::iterator it = partition(results.begin(), results.end(), Three());

	for_each(results.begin(), it, print);
	cout << endl;
	for_each(it, results.end(), print);
	cout << endl;

	system("pause");
	return 0;
}