Submission #495601

#	Time	Username	Problem	Language	Result	Execution time	Memory
495601		Victor	Diversity (CEOI21_diversity)	C++17	64 / 100	110 ms	14124 KiB

diversity

// #pragma GCC target ("avx,avx2,fma")
// #pragma GCC optimize ("Ofast,inline") // O1 - O2 - O3 - Os - Ofast
// #pragma GCC optimize ("unroll-loops")
#include <bits/stdc++.h>

using namespace std;

#define rep(i, a, b) for (int i = (a); i < (b); ++i)
#define per(i, a, b) for (int i = (b - 1); i >= (a); --i)
#define trav(a, x) for (auto &a : x)

#define all(x) x.begin(), x.end()
#define sz(x) x.size()
#define pb push_back
#define debug(x) cout << #x << " = " << x << endl

#define umap unordered_map
#define uset unordered_set

typedef pair<int, int> ii;
typedef pair<int, ii> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<vi> vvi;

typedef long long ll;
typedef pair<ll, ll> pll;
typedef vector<ll> vll;
typedef vector<pll> vpll;

const int INF = 1'000'000'007;

int n, arr[300001], q;

int main() {
    cin.tie(0)->sync_with_stdio(0);
    cin.exceptions(cin.failbit);

    umap<int, int> ttoi;
    vii types;
    cin >> n >> q;
    rep(i, 0, n) {
        int type;
        cin >> type;

        if (!ttoi.count(type)) {
            types.emplace_back(0, sz(ttoi));
            ttoi[type] = sz(types) - 1;
        }
        ++types[ttoi[type]].first;
    }

    sort(all(types));
    n = sz(types);
    int lo = 0, hi = n - 1;
    bool side = 0;

    ll ans = 0;
    trav(item, types) {
        int type, cnt;
        tie(cnt, type) = item;

        if (side)
            arr[hi--] = cnt;
        else
            arr[lo++] = cnt;
        side ^= 1;
        ans += ll(cnt) * (cnt + 1) / 2;
    }

    if (q == 1) {

        ll prefix=0,fac=0;
        rep(i, 0, n){
            ans+=arr[i]*fac;
            prefix+=arr[i];
            fac+=prefix+arr[i];
        }
        cout << ans << endl;
    }
    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