Submission #971686

#	Time	Username	Problem	Language	Result	Execution time	Memory
971686		Szil	Diversity (CEOI21_diversity)	C++17	64 / 100	7091 ms	8768 KiB

diversity

#include <bits/stdc++.h>
 
using namespace std;
using ll = long long;
 
const int MAXN = 300'001;
const int BLOCK = 400;

struct Query {
    int l, r, idx;
 
    bool operator<(Query x) const {
        if (l / BLOCK == x.l / BLOCK) return (l / BLOCK) & 1 ? r > x.r : r < x.r;
        return l < x.l;
    }
};
 
int a[MAXN], b[MAXN]; 
map<int, int> c;
ll ans[MAXN], negyzet[MAXN];
 
void add(int i) {
    int v = a[i];
    if (b[v]) {
        c[b[v]]--;
        if (c[b[v]] == 0) c.erase(b[v]);
    }
    b[v]++;
    c[b[v]]++;
}
 
void remove(int i) {
    int v = a[i];
    c[b[v]]--;
    if (c[b[v]] == 0) c.erase(b[v]);
    b[v]--;
    if (b[v]) {
        c[b[v]]++;
    }
}
 
int main() {
    ios::sync_with_stdio(0); cin.tie(0);
    int n, q; cin >> n >> q;
    for (ll i = 1; i <= n; i++) {
        negyzet[i] = negyzet[i-1] + i*i;
    }
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
    }
    vector<Query> qrys(q);
    for (int i = 0; i < q; i++) {
        cin >> qrys[i].l >> qrys[i].r;
        qrys[i].idx = i+1;
    }
    sort(qrys.begin(), qrys.end());
    int l = 1, r = 0;
    for (auto [nl, nr, idx] : qrys) {
        while (r < nr) add(++r);
        while (r > nr) remove(r--);
        while (l < nl) remove(l++);
        while (l > nl) add(--l);
 
        deque<pair<ll, ll>> dq;
        int d = 0;
 
        auto push = [&](int a, int b) {
            if (d) dq.emplace_back(a, b);
            else dq.emplace_front(a, b);
            d ^= 1;
        };


        for (auto it = c.rbegin(); it != c.rend(); it++) {
            auto [len, cnt] = *it;
            if (cnt & 1) {
                push(len, 1);
                cnt--;
            }
            push(len, cnt/2);
            push(len, cnt/2);
        }
 
        auto sum_arit = [&](ll start, ll d, ll cnt) {
            return start*cnt + d * (cnt - 1) * cnt / 2;
        };
 
        ll pref = 0;
        int x = nr-nl+1;
        for (auto [len, cnt] : dq) {
            ans[idx] += cnt * (len*(len+1)/2);
            ans[idx] += cnt * (len*(x-len));
            ans[idx] += (x - len) * sum_arit(pref, len, cnt);
            ans[idx] -= pref * pref * cnt;
            ans[idx] -= pref * sum_arit(0, 2*len, cnt);
            ans[idx] -= len * len * negyzet[cnt-1];
            pref += len*cnt;
        }
    }
 
    for (int i = 1; i <= q; i++) {
        cout << ans[i] << "\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