Submission #760153

#	Time	Username	Problem	Language	Result	Execution time	Memory
760153		The_Samurai	Party (INOI20_party)	C++17	23 / 100	3078 ms	468 KiB

Main

#include "bits/stdc++.h"

using namespace std;
using ll = long long;

const ll mod = 1e9 + 7;

ll binpow(ll a, ll b, ll mod, bool dec = false) {
    ll ans = 1;
    while (b) {
        if (b & 1) {
            ans = ans * a % mod;
        }
        a = a * a % mod;
        b >>= 1;
    }
    if (dec) {
        ans = (ans - 1 + mod) % mod;
    }
    return ans;
}

bool isTwo(ll n) {
    return (1ll << (63 - __builtin_clzll(n))) == n;
}

ll n, ans;

void calc(ll x, ll mul) {
    vector<tuple<ll, ll, bool>> g = {{x, 1, true}};
    ll others = n, sum_all = 0;
    for (int h = 0; h <= n; h++) {
        vector<tuple<ll, ll, bool>> nw;
        ll sum = 0;
        for (auto [v, t, change]: g) {
            sum += t;
            if (!change) {
                if (v * 2 <= n) {
                    nw.emplace_back(v * 2, t * 2, change);
                }
                continue;
            }
            if (x == v) {
                if (v * 2 <= n) {
                    nw.emplace_back(v * 2, t * 2, false);
                }
                if (v > 1) {
                    nw.emplace_back(v / 2, 1, true);
                }
                continue;
            }
            if (isTwo(x / v) and x % v == 0) {
                if (v * 2 + 1 <= n) {
                    nw.emplace_back(v * 2 + 1, 1, false);
                }
                if (v > 1) {
                    nw.emplace_back(v / 2, 1, true);
                }
                continue;
            }
        }
        others -= sum;
        ll k = binpow(2, sum, mod, true) * binpow(2, others, mod) % mod;
        sum_all = (sum_all + k * h) % mod;
        if (nw.empty()) {
            break;
        }
        g = nw;
    }
    mul %= mod;
    ans = (ans + sum_all * mul) % mod;
}

int main() {
    ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
    int q;
    cin >> q;
    map<ll, int> mp;
    for (int qq = 1; qq <= q; qq++) {
        cin >> n;
//        n = (1ll << 59) - 1;
        if (mp.count(n)) {
            cout << mp[n] << '\n';
            continue;
        }
        ans = 0;
        for (ll x = 1; x < n; x *= 2) {
            calc(x, x);
        }
        ans = ans * binpow(binpow(2, n, mod, true), mod - 2, mod) % mod;
        cout << ans << '\n';
        mp[n] = ans;
    }
}

• Subtask 1: 0 / 7
• Subtask 2: 23 / 23
• Subtask 3: 0 / 33
• Subtask 4: 0 / 37