数组

#include <bits/stdc++.h>
#define int long long
using namespace std;

vector<int> a;

signed main() {
	int n;
	cin >> n;

	for (int i = 1; i <= n; i++) {
		int x;
		cin >> x;
		a.push_back(x);
	}

	sort(a.begin(), a.end());
	a.erase(unique(a.begin(), a.end()), a.end());

	cout << a.size() << "\n";

//	for (auto x : a)
//		cout << x << " ";

	for (int i = 0; i < a.size(); i++) {
		cout << a[i] << " ";
	}
}

#include <bits/stdc++.h>
#define int long long
using namespace std;

int a[110];

signed main() {
	int n, m;
	cin >> n >> m;

	for (int i = 1; i <= n; i++) {
		cin >> a[i];
	}

	int sum = 0;
	for (int i = 1; i <= m; i++) {
		sum += a[i];
	}

	double avg = sum * 1.0 / m;
	int l = 1, r = m;

	double ans = avg;

	while (r != n) {
		sum -= a[l];
		sum += a[r + 1];

		avg = sum * 1.0 / m;
		ans = max(ans, avg);

		r++;
		l++;
	}

	cout << fixed << setprecision(2) << ans;
}

```cpp
#include <bits/stdc++.h>
#define int long long
using namespace std;

int a[50];

signed main() {
	int n;
	cin >> n;
	for (int i = 1; i <= n; i++) {
		cin >> a[i];
		a[n + i] = a[i];
	}

	int sum = 0, ans = 0, idx=0;
	for (int i = 1; i <= 4; i++) {
		sum += a[i];
	}

	int l = 1, r = 4;
	// ans = max(ans, sum);
    if(sum > ans) {
        ans = sum;
        idx = l;
    }

	while (r != n * 2) {
		sum -= a[l];
		sum += a[r + 1];

		l++;
		r++;

        if(sum > ans) {
            ans = sum;
            idx = l;
        }
	}

	cout << ans <<"\n"<<idx;
}