test.cc

#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
using namespace std;

int main(void)
{
  vector<int> vc;
	int n;
	cout << "# of data" << endl;
	cin >> n;

	int x;
	double avg = 0;
	for(int i = 0; i < n; i++)
	{
		cin >> x;
		avg += x;
		vc.push_back(x);
	}
	avg /= n;

	sort(vc.begin(), vc.end());

	for(int i = 0; i < n; i++)
	{
		cout << vc[i] << '\t';
		if(i % 5 == 4)
			cout << endl;
	}

	int mode = 0;
	{
		int maxmode = 0;
		int curmode = 0;
		for(int i = 1; i < n; i++)
		{
			if(vc[i] == vc[i - 1])
				curmode++;
			else
				curmode = 0;
			if(curmode > maxmode)
			{
				mode = vc[i];
				maxmode = curmode;
			}
		}
	}

	double median = (n % 2 == 0)? ((vc[n/2] + vc[n/2 + 1])/2) : vc[n/2 + 1];

	cout << "avg = " << avg << endl;
	cout << "mode = " << mode << endl;
	cout << "median = " << median << endl;

	double SD = 0;
	for(int i = 0; i < n; i++)
	{
		SD += (vc[i] - avg) * (vc[i] - avg);
	}
	SD /= (n - 1);
	SD = sqrt(SD);

	cout << "SD = " << SD << endl;

	return 0;
}