pentagonal.cpp

包含C++中map

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

using namespace std;

bool calc_elements(vector<int> &vec,int pos)
{
	if(pos<=0 || pos>50)
	{
		cerr << "Sorry.It is a invalid position !";
		return false;
	}

	for (int ix=vec.size()+1;ix<=pos;++ix)
		vec.push_back((ix*(3*ix-1))/2);
	
	return true;
}

void display_elements(vector<int> &vec,const string &title,ostream &os=cout)
{
	os << "\n" << title << "\t";
	for(int ix=0;ix<vec.size();++ix)
		os << vec[ix] << "  ";
	os << endl;
}

int main()
{
	vector<int> pent;
	const string title("Pentagonal Numeric Series ");

	if(calc_elements(pent,0))
		display_elements(pent,title);

	if(calc_elements(pent,6))
		display_elements(pent,title);

	if(calc_elements(pent,10))
		display_elements(pent,title);

	if(calc_elements(pent,100))
		display_elements(pent,title);
	cout << endl;
	return 0;
}