Submission #799315

#	Time	Username	Problem	Language	Result	Execution time	Memory
799315		Johann	Diversity (CEOI21_diversity)	C++14	64 / 100	7076 ms	8812 KiB

diversity

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

typedef long long ll;
typedef vector<ll> vi;
typedef pair<ll, ll> pii;
typedef vector<pii> vpii;
#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 split(int x)
{
    vi sp;
    if (x == 1)
        sp.push_back(1);
    else
    {
        sp.push_back(x / 2);
        sp.push_back(x / 2);
        if (x & 1)
            sp.push_back(1);
    }
    return sp;
}

ll numberOfSubsequences(ll n)
{
    return n * (n + 1) / 2;
}
ll totalLengthOfSubsequences(ll n)
{
    return n * (n + 1) * (n + 1) / 2 - (2 * n + 1) * (n + 1) * n / 6;
}

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;
            A = vi(AA.begin() + l, AA.begin() + r);
        }
        ll n = sz(A);

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

        map<int, int> cnts;
        for (int i = 0; i < sz(heatMap); ++i)
            if (heatMap[i])
                ++cnts[heatMap[i]];

        vpii S;
        for (auto it = cnts.begin(); it != cnts.end(); ++it)
            for (int x : split(it->second))
                S.push_back({it->first, x});

        ll left = 0, right = 0;
        int num = sz(S);

        ans = totalLengthOfSubsequences(n);

        for (int j = 0; j < num; ++j)
        {

            ll x = S[j].first;  // how much
            ll y = S[j].second; // how often
            ll len = x * y;

            // if both are in set
            ans -= totalLengthOfSubsequences(len) - x * x * (totalLengthOfSubsequences(y) - y) - y * numberOfSubsequences(x);
            // if one is inside the other isn't
            ans -= (n - len) * (len * (len + 1) / 2 - x * y * (y + 1) / 2);
            // if both are outside
            ans -= (len - y) * left * (n - left - len);

            left += len;
            swap(left, right);
        }
        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