Submission #697530

#	Time	Username	Problem	Language	Result	Execution time	Memory
697530		piOOE	Diversity (CEOI21_diversity)	C++17	64 / 100	7029 ms	14692 KiB

diversity

#include <bits/stdc++.h>

using namespace std;
using ll = long long;

struct SmartFenwick {
    vector<ll> k, b;
    int n{};

    void init(int x) {
        n = x;
        k.resize(x + 1), b.resize(x + 1);
    }

    void addk(int i, ll v) {
        for (int x = i + 1; x <= n; x += x & -x) {
            k[x] += v;
        }
    }

    void addb(int i, ll v) {
        for (int x = i + 1; x <= n; x += x & -x) {
            b[x] += v;
        }
    }

    void rangeAdd(int l, int r, ll v) {
        addk(l, v);
        addk(r, -v);
        addb(l, (l - 1) * -v);
        addb(r, (r - 1) * v);
    }

    ll sum(int i) {
        ll K = 0, B = 0;

        for (int x = i + 1; x > 0; x -= x & -x) {
            K += k[x], B += b[x];
        }

        return B + K * i;
    }

    ll rangeSum(int l, int r) {
        return sum(r - 1) - sum(l - 1);
    }
} t[2][2]; // (left/right), (L/R)

struct Query {
    int l, r, block, idx;

    bool operator<(Query oth) const {
        if (oth.block != block) {
            return block < oth.block;
        }

        return (block & 1) ? r > oth.r : r < oth.r;
    }
};

constexpr int B = 1000;

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();

    vector<Query> queries(q);
    vector<ll> answer(q);

    for (int i = 0; i < q; ++i) {
        int l, r;
        cin >> l >> r;
        l -= 1;

        queries[i].l = l, queries[i].r = r, queries[i].block = l / B, queries[i].idx = i;
    }

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

    vector<int> head(n + 1);

    for (int i = 1; i <= n; ++i) {
        head[i] = m;
    }


    vector<int> pos(m), cnt(m), ord(m);
    iota(pos.begin(), pos.end(), 0);
    ord = pos;

    int siz[2]{(m + 1) / 2, m / 2};

    t[0][0].init(siz[0]);
    t[0][1].init(siz[0]);
    t[1][0].init(siz[1]);
    t[1][1].init(siz[1]);

    ll ans = 0;

    int len = 0;

    auto eval = [&](int i) {
        return 1LL * cnt[i] * (len - cnt[i]) + 1LL * (cnt[i] + 1) * cnt[i] / 2;
    };

    auto increase = [&](int i) {
        ans += len;

        len += 1;

        ans -= eval(i);

        int p = pos[i];
        int tail = head[cnt[i] + 1] - 1;

        if (p != tail) {
            int id = ord[tail];
            pos[id] = p;
            ord[p] = id;
            pos[i] = tail;
            ord[tail] = i;
            p = tail;
        }

        int side = p % 2;
        int s = p / 2;

        ans += t[side][side ^ 1].rangeSum(s + 1, siz[side]);
        t[side][side].rangeAdd(s + 1, siz[side], 1);

        t[side][side ^ 1].rangeAdd(0, s, 1);
        ans += t[side][side].rangeSum(0, s);

        ans += t[side ^ 1][side ^ 1].rangeSum(0, siz[side ^ 1]);
        t[side ^ 1][side].rangeAdd(0, siz[side ^ 1], 1);

        cnt[i] += 1;
        head[cnt[i]] = p;

        ans += eval(i);
    };

    auto decrease = [&](int i) {
        ans -= len;

        len -= 1;

        ans -= eval(i);

        int p = pos[i];
        int start = head[cnt[i]];

        if (p != start) {
            int id = ord[start];
            pos[id] = p;
            ord[p] = id;
            pos[i] = start;
            ord[start] = i;
            p = start;
        }

        int side = p % 2;
        int s = p / 2;

        ans -= t[side][side ^ 1].rangeSum(s + 1, siz[side]);
        t[side][side].rangeAdd(s + 1, siz[side], -1);

        t[side][side ^ 1].rangeAdd(0, s, -1);
        ans -= t[side][side].rangeSum(0, s);

        ans -= t[side ^ 1][side ^ 1].rangeSum(0, siz[side ^ 1]);
        t[side ^ 1][side].rangeAdd(0, siz[side ^ 1], -1);

        head[cnt[i]] = p + 1;
        cnt[i] -= 1;

        ans += eval(i);
    };

    int lx = 0, rx = 0;

    for (auto [l, r, bl, i] : queries) {
        while (rx < r) {
            increase(a[rx++]);
        }

        while (lx > l) {
            increase(a[--lx]);
        }

        while (lx < l) {
            decrease(a[lx++]);
        }

        while (rx > r) {
            decrease(a[--rx]);
        }

        answer[i] = ans;
    }

    for (int i = 0; i < q; ++i) {
        cout << answer[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