Submission #999280

#	Time	Username	Problem	Language	Result	Execution time	Memory
999280		crafticat	Diversity (CEOI21_diversity)	C++17	4 / 100	9 ms	3344 KiB

diversity

#include <bits/stdc++.h>

using namespace std;
using ll = long long;
using pii = pair<ll,ll>;

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

    ll n, q; cin >> n >> q;
    vector<ll> arr(n);
    for (ll i = 0; i < n; ++i) {
        cin >> arr[i];
    }
    for (ll i = 0; i < q; ++i) {
        ll l, r; cin >> l >> r;
        l--;
        ll bestAns = 1e18;
        for (int m = 0; m < 20; ++m) {
            vector<ll> v;
            vector<ll> app(300002);
            v.reserve(r - l);
            ll s = r - l;
            for (ll j = l; j < r; ++j) {
                v.push_back(arr[j]);
            }
            for (auto x : v) {
                app[x]++;
            }
            vector<pii> v2;
            for (auto x : v) {
                v2.emplace_back(app[x],x);
            }
            std::sort(v2.begin(), v2.end());
            vector<pii> orderA, orderB;
            ll last = -1;
            ll leftS = 0, rightS = 0;
            bool dir = true;
            for (auto [a, x] : v2) {
                if (last != x) {
                    dir = !dir;
                    if (rand() % 2) {
                        orderA.emplace_back(x, a);
                        leftS += a;
                    }
                    else {
                        orderB.emplace_back(x,a);
                        rightS += a;
                    }
                }
                last = x;
            }
            vector<pii> order;
            for (auto x : orderA) {
                order.push_back(x);
            }
            std::reverse(orderB.begin(), orderB.end());
            for (auto x : orderB) {
                order.push_back(x);
            }

            ll a = 0;
            ll ans = 0;
            for (auto [x, amount] : order) {
                ll b = a + amount;
                ll includeSub = a * (s - b);
                ll includePar = a * amount + (s - b) * amount;
                ll self = amount * (amount + 1) / 2;
                ans += self + includePar + includeSub;
                a += amount;
            }
            bestAns = min(ans, bestAns);
        }

        cout << bestAns << "\n";
    }

    return 0;
}

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