Submission #894401

#	Time	Username	Problem	Language	Result	Execution time	Memory
894401		vjudge1	Rack (eJOI19_rack)	C++17	100 / 100	11 ms	2328 KiB

rack

#include <bits/stdc++.h>
using namespace std;

#define speed ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define rall(x) x.rbegin(), x.rend()
#define all(x) x.begin(), x.end()
#define sz(x) (int)x.size()
#define mp make_pair
#define pb push_back
#define F first
#define S second
#define nl '\n'
#define int long long

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef long double ld;

const int N = 1e6 + 5;
const int M = 1e3 + 5;
const int inf = 1e9 + 123;
const ll infl = 1e15 + 10;
const int mod = 1e9 + 7;
const int P = 31;

ll n, k;
vector <pair <string, int> > ans;

void go(int v, int tl, int tr, string s){
    if(tl == tr){
        reverse(all(s));
        ans.pb(mp(s, tl));
        return;
    }
    int tm = (tl + tr) >> 1;
    go(v + v, tl, tm, s + '0');
    go(v + v + 1, tm + 1, tr, s + '1');
}

ll mul(ll a, ll b){
    return 1LL * a * b % mod;
}

ll get(string s){
    ll ans = 0;
    for(int i = sz(s) - 1; i >= 0; i--){
        ans = mul(ans, 2);
        ans += s[i] - '0';
        ans %= mod;
    }
    return ++ans;
}

string conv(ll t){
    string ret = "";
    while(t){
        ret += char('0' + t % 2);
        t >>= 1;
    }
    reverse(all(ret));
    return ret;
}

void solve() {
    cin >> n >> k;
    --k;
    string t = conv(k);
    reverse(all(t));
    while(sz(t) < n)
        t.pb('0');
    reverse(all(t));
    cout << get(t) << nl;
}

signed main() {
    speed;
    int T = 1;
    // cin >> T;
    while (T--)
        solve();
}

• Subtask 1: 20 / 20
• Subtask 2: 20 / 20
• Subtask 3: 60 / 60