[2108] 통계학

#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
using namespace std;
bool comp(const pair<int, int> &p1, const pair<int, int> &p2)
{
	if (p1.second == p2.second)
		return p1.first < p2.first;
	else
		return p1.second > p2.second;
}
int main()
{
	int num, sum=0;
	double avg;
	cin >> num;
	vector <int> v(num);
	
	for (int i = 0; i < num; i++)
		cin >> v[i];
	for (int i = 0; i < v.size(); i++)
		sum += v[i];
	avg = sum / num;
	sort(v.begin(), v.end());
	cout.precision(1);
	cout << floor(avg+0.5) << endl;
	cout << v[num / 2] << endl;
	vector<pair<int, int> > st;
	vector<int>::size_type i;
	for (i = 0; i<v.size(); i++)
	{
		if (st.empty())
		{
			st.push_back(pair<int, int>(v[i], 1));
			continue;
		}
		if (st.back().first == v[i])
		{
			pair<int, int> tmp = st.back();
			tmp.second++;
			st.pop_back();
			st.push_back(tmp);
		}
		else
			st.push_back(pair<int, int>(v[i], 1));
	}
	sort(st.begin(), st.end(), comp);
	if (st[0].second == st[1].second)
		cout << st[1].first << endl;
	else
		cout << st[0].first << endl;
	cout << v.back() - v.front() << endl;
	return 0;
}