Submission #1283335

#	Time	Username	Problem	Language	Result	Execution time	Memory
1283335		kawhiet	Diversity (CEOI21_diversity)	C++20	64 / 100	44 ms	8160 KiB

diversity

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

#define int long long

#ifdef LOCAL
#include "debug.h"
#else
#define dbg(...) 42
#endif

constexpr int N = 3e5 + 1;

int cnt[N];

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n, q;
    cin >> n >> q;
    for (int i = 0; i < n; i++) {
        int x;
        cin >> x;
        cnt[x]++;
    }
    while (q--) {
        int l, r;
        cin >> l >> r;
    }
    vector<int> a;
    for (int i = 1; i < N; i++) {
        if (cnt[i] > 0) {
            a.push_back(cnt[i]);
        }
    }
    sort(a.rbegin(), a.rend());
    n = a.size();
    deque<int> b;
    for (int i = 0; i < n; i++) {
        if (i % 2 == 0) {
            b.push_back(a[i]);
        } else {
            b.push_front(a[i]);
        }
    }
    int res = 0;
    vector<int> s(n + 1);
    for (int i = n - 1; i >= 0; i--) {
        s[i] = s[i + 1] + b[i];
    }
    int sum = 0;
    for (int i = 0; i < n; i++) {
        sum += b[i] * (i + 1);
    }
    for (int i = 0; i < n; i++) {
        res += b[i] * sum;
        sum -= s[i];
    }
    for (int i = 0; i < n; i++) {
        res -= b[i] * (b[i] - 1) / 2;
    }
    cout << res << '\n';
    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