Submission #659704

#	Time	Username	Problem	Language	Result	Execution time	Memory
659704		Sohsoh84	Diversity (CEOI21_diversity)	C++17	64 / 100	862 ms	3776 KiB

diversity

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef pair<ll, ll> pll;

#define all(x)			(x).begin(),(x).end()
#define X			first
#define Y			second
#define sep			' '
#define endl			'\n'
#define debug(x)		cerr << #x << ": " <<  x << endl;

const ll MAXN = 1e6 + 10;
const ll INF = 4e18;

int n, q, cnt[MAXN], A[MAXN];

int main() {
	ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
	cin >> n >> q;
	for (int i = 1; i <= n; i++) {
		int A[i];
		cin >> A[i];
		cnt[A[i]]++;
	}

	vector<int> vec = {0};
	for (int i = 0; i < MAXN; i++)
		if (cnt[i])
			vec.push_back(cnt[i]);

	int m = vec.size() - 1;
	sort(all(vec));

	ll s = 0, ans = 0, j = 0;
	for (int i = 1; i <= m; i++) {	
		if (i & 1) {
			j += vec[i];
			ans += j * (n - j); // n * j - j * j
		} else ans += (s - j) * (n - s + j);

		s += vec[i];
	}

	cout << ans + 1ll * n * (n + 1) / 2 << endl;
	return 0;
}

• Subtask 1: 4 / 4
• Subtask 2: 10 / 10
• Subtask 3: 8 / 8
• Subtask 4: 16 / 16
• Subtask 5: 26 / 26
• Subtask 6: 0 / 36