Submission #798553

#	Time	Username	Problem	Language	Result	Execution time	Memory
798553		Johann	Diversity (CEOI21_diversity)	C++14	22 / 100	995 ms	3532 KiB

diversity

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

typedef long long ll;
typedef vector<int> vi;
#define sz(x) (int)(x).size()
#define all(x) (x).begin(), (x).end()

const ll INF = 1e18;
int N, Q;
vi A, AA;
ll ans;
vi P;
vi answerPermutation;

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);

    cin >> N >> Q;
    AA.resize(N);
    for (int i = 0; i < N; ++i)
        cin >> AA[i];

    while (Q--)
    {
        int l, r;
        cin >> l >> r;
        --l;
        ll n = r - l;

        A = vi(AA.begin() + l, AA.begin() + r);

        vi heatMap(*max_element(all(A)) + 1, 0);
        for (int i = 0; i < sz(A); ++i)
            ++heatMap[A[i]];
        vi cnts;
        for (int i = 0; i < sz(heatMap); ++i)
            if (heatMap[i])
                cnts.push_back(heatMap[i]);

        sort(all(cnts));
        ll num = sz(cnts);
        ans = INF;

        for (int i = 0; i < (1 << num); ++i)
        {
            // if all were different
            ll tmp = n * (n + 1) * (n + 1) / 2 - (2 * n + 1) * (n + 1) * n / 6;

            ll right = 0;
            ll left = 0;

            for (int j = 0; j < num; ++j)
            {
                ll x = cnts[j];
                // either with left or right endpoint in set
                tmp -= (n - x) * x * (x - 1) / 2;
                // if both are in set
                tmp -= x * x * (x - 1) / 2 - (2 * x - 1) * x * (x - 1) / 6;

                if (i & (1 << j))
                { // left
                    tmp -= (x - 1) * left * (n - left - x);
                    left += x;
                }
                else
                { // right
                    tmp -= (x - 1) * right * (n - right - x);
                    right += x;
                }
            }
            ans = min(ans, tmp);
        }

        cout << ans << "\n";
    }

    return 0;
}

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