Submission #678199

#	Time	Username	Problem	Language	Result	Execution time	Memory
678199		stanislavpolyn	Diversity (CEOI21_diversity)	C++17	4 / 100	8 ms	1744 KiB

diversity

#include <bits/stdc++.h>

#define fr(i, a, b) for (int i = (a); i <= (b); ++i)
#define rf(i, a, b) for (int i = (a); i >= (b); --i)
#define fe(x, y) for (auto& x : y)

#define fi first
#define se second
#define pb push_back
#define mp make_pair
#define mt make_tuple

#define all(x) (x).begin(), (x).end()
#define pw(x) (1LL << (x))
#define sz(x) (int)(x).size()

using namespace std;

mt19937_64 rng(chrono::system_clock::now().time_since_epoch().count());

//mt19937_64 rng(228);

#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
template <typename T>
using oset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define fbo find_by_order
#define ook order_of_key

template <typename T>
bool umn(T& a, T b) {
    return a > b ? a = b, 1 : 0;
}
template <typename T>
bool umx(T& a, T b) {
    return a < b ? a = b, 1 : 0;
}

using ll = long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
template <typename T>
using ve = vector<T>;

int calc(ve<int> a) {
    int ans = 0;
    fr (i, 0, sz(a) - 1) {
        set<int> s;
        fr (j, i, sz(a) - 1) {
            s.insert(a[j]);
            ans += sz(s);
        }
    }
    return ans;
}


ll calc2(ve<int> a) {
    int total = 0;
    fe (x, a) total += x;
    ll ans = 0;
    int toLeft = 0;
    fr (i, 0, sz(a) - 1) {
        int toRight = total - toLeft - a[i];
        ans += 1LL * total * (total + 1) / 2;
        ans -= 1LL * toLeft * (toLeft + 1) / 2;
        ans -= 1LL * toRight * (toRight + 1) / 2;
        toLeft += a[i];
    }
    return ans;
}

const int N = 3e5 + 5;

int n, q;
int a[N];

int cnt[N];

int rnd(int l, int r) {
    return rng() % (r - l + 1) + l;
}

int solve(ve<int> a) {
    fe (x, a) cnt[x] = 0;

    fe (x, a) cnt[x]++;

    ve<pii> order;
    fe (x, a) {
        if (cnt[x]) {
            order.pb({cnt[x], x});
            cnt[x] = 0;
        }
    }
    sort(all(order));
    reverse(all(order));

    deque<int> d;
    bool who = 0;
    fe (cur, order) {
        if (who == 0) d.push_front(cur.fi);
        else d.pb(cur.fi);
        who ^= 1;
    }
    ve<int> v;
    int now = 1;
    fe (x, d) {
        v.pb(x);
    }
    return calc2(v);
}



int main() {
#ifdef LOCAL
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#else
    ios::sync_with_stdio(0);
    cin.tie(0);
#endif

    cin >> n >> q;

    ve<int> v;
    fr (i, 1, n) {
        cin >> a[i];
        v.pb(a[i]);
    }

    sort(all(v));

    cout << solve(v) << "\n";


//    int mn = 1e9;
//    do {
//        umn(mn, calc(v));
//    } while (next_permutation(all(v)));
//
//    cout << solve(v) << " " << mn << "\n";
//
//    do {
//        if (calc(v) == mn) {
//            cout << "v: ";
//            fe (x, v) cout << x << " ";
//            cout << "\n";
//        }
//    } while (next_permutation(all(v)));


    return 0;
}

Compilation message (stderr)

diversity.cpp: In function 'int solve(ve<int>)':
diversity.cpp:108:9: warning: unused variable 'now' [-Wunused-variable]
  108 |     int now = 1;
      |         ^~~

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