Submission #697515

#	Time	Username	Problem	Language	Result	Execution time	Memory
697515		piOOE	Diversity (CEOI21_diversity)	C++17	64 / 100	107 ms	5584 KiB

diversity

#include <bits/stdc++.h>

using namespace std;
using ll = long long;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int n, q;
    cin >> n >> q;

    vector<int> a(n);

    for (int i = 0; i < n; ++i) {
        cin >> a[i];
    }

    vector<int> yy = a;
    sort(yy.begin(), yy.end());
    yy.resize(unique(yy.begin(), yy.end()) - yy.begin());

    for (int &x : a) {
        x = lower_bound(yy.begin(), yy.end(), x) - yy.begin();
    }

    const int m = yy.size();

    int L, R;
    cin >> L >> R;

    assert(q == 1 && L == 1 && R == n);

    vector<int> cnt(m);

    for (int x : a) {
        cnt[x] += 1;
    }

    ll ans = 0;

    for (int x : cnt) {
        ans += 1LL * x * (x + 1) / 2 + 1LL * x * (n - x);
    }

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

    int l = 0, r = 0;

    for (int x : cnt) {
        if (l < r) {
            ans += 1LL * l * (n - x - l);
            l += x;
        } else {
            ans += 1LL * r * (n - x - r);
            r += x;
        }
    }

    cout << ans << '\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