Submission #1003368

#	Time	Username	Problem	Language	Result	Execution time	Memory
1003368		vjudge1	Party (INOI20_party)	C++17	0 / 100	112 ms	348 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 rng(chrono::steady_clock::now().time_since_epoch().count());
template<class T> using ordered_set = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>;
const ll mod = 1e9 + 7;
ll binpow(ll n, ll p)
{
    ll ans = 1;
    while (p)
    {
        ans = (p & 1 ? (ans * n) % mod : ans);
        n = (n * n) % mod;
        p >>= 1;
    }
    return ans;
}
ll inv(ll x)
{
    return binpow(x, mod - 2);
}
void solve()
{
    ll n;
    cin >> n;
    ll ans = 0, lg = __lg(n);
    ll freq[120];
    for (ll i = 0; i <= lg; i++)
    {
        ll res = 0;
        for (ll j = 0; j < 120; j++) freq[j] = 0;
        for (ll j = 1; j <= i; j++){
            freq[j] = (freq[j] + 1) % mod;
            for (ll x = 1; i - j + x <= lg; x++) freq[j + x] = (freq[j + x] + binpow(2, x - 1)) % mod;
        }
        for (ll x = 1; x + i <= lg; x++) freq[x] = (freq[x] + binpow(2, x)) % mod;
        ll cur = 0;
        for (ll j = 119; j >= 0; j--)
            res = (res + binpow(2, cur) * (binpow(2, freq[j]) - 1) % mod * j % mod) % mod, cur += freq[j];
        ans = (ans + binpow(2, i) * res % mod) % mod;
    }
    ans = ans * inv(binpow(2, n) - 1 + mod) % mod;
    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: 0 / 7
• Subtask 2: 0 / 23
• Subtask 3: 0 / 33
• Subtask 4: 0 / 37