제출 #1142758

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1142758		Nelt	Izbori (COCI22_izbori)	C++20	25 / 110	3095 ms	13820 KiB

Main

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ll long long
#define endl "\n"

using namespace std;
using namespace __gnu_pbds;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
template <typename T, typename key = less_equal<T>>
using ordered_set = tree<T, null_type, key, rb_tree_tag, tree_order_statistics_node_update>;
const ll N = 2e5 + 5, B = 450, offset = 2e5 + 1;
ll t[N * 2], cnt[N], pref[N];
ll sum(ll i)
{
    ll res = 0;
    for (; i >= 0; i = (i & (i + 1)) - 1)
        res += t[i];
    return res;
}
void upd(ll i, ll d)
{
    for (; i < N * 2; i = (i | (i + 1)))
        t[i] += d;
}
void solve()
{
    ll n;
    cin >> n;
    ll a[n + 1];
    vector<ll> freq[n + 1];
    for (ll i = 1; i <= n; i++)
        cin >> a[i];
    {
        ll b[n];
        for (ll i = 1; i <= n; i++)
            b[i - 1] = a[i];
        sort(b, b + n);
        for (ll i = 1; i <= n; i++)
            a[i] = lower_bound(b, b + n, a[i]) - b + 1;
    }
    // for (ll i = 1; i <= n; i++) cout << a[i] << " ";
    for (ll i = 1; i <= n; i++)
        freq[a[i]].push_back(i);
    multiset<ll> s;
    ll ans = 0;
    for (ll x = 1; x <= min(B, n); x++)
    {
        for (ll i = 1; i <= n; i++)
            cnt[i] = 0;
        s.clear();
        for (ll i = 1; i <= x; i++)
            cnt[a[i]]++;
        for (ll i = 1; i <= n; i++)
            s.insert(cnt[i]);
        if (*s.rbegin() > x / 2)
            ans++;
        for (ll i = x + 1; i <= n; i++)
        {
            if (a[i] != a[i - x])
            {
                s.erase(s.find(cnt[a[i - x]]));
                s.erase(s.find(cnt[a[i]]));
                cnt[a[i - x]]--;
                cnt[a[i]]++;
                s.insert(cnt[a[i - x]]);
                s.insert(cnt[a[i]]);
            }
            if (*s.rbegin() > x / 2)
                ans++;
        }
    }
    for (ll x = 1; x <= n; x++)
        if (freq[x].size() * 2 > B)
        {
            pref[0] = 0;
            for (ll i = 1; i <= n; i++)
                pref[i] = pref[i - 1] + (a[i] == x ? 1 : -1);
            for (ll i = 0; i <= n * 2 + 5; i++)
                t[i] = 0;
            for (ll i = B + 1; i <= n; i++)
            {
                upd(pref[i - B - 1] + offset, 1);
                ans += sum(pref[i] + offset - 1);
            }
        }
    cout << ans << endl;
}

int main()
{
    // ios_base::sync_with_stdio(0);
    // cin.tie(0);
    ll t = 1;
    // precomp();
    // cin >> t;
    for (ll cs = 1; cs <= t; cs++)
        solve();
    // cerr << "\nTime elapsed: " << clock() * 1000.0 / CLOCKS_PER_SEC << " ms\n";
}

• Subtask 1: 10 / 10
• Subtask 2: 15 / 15
• Subtask 3: 0 / 15
• Subtask 4: 0 / 70