Submission #465888

#	Time	Username	Problem	Language	Result	Execution time	Memory
465888		spike1236	Rack (eJOI19_rack)	C++14	100 / 100	9 ms	4032 KiB

rack

#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define mp make_pair
#define f first
#define s second
#define ll long long
#define ld long double
#define all(_v) _v.begin(), _v.end()
#define sz(_v) (int)_v.size()
#define pii pair <int, int>
#define pll pair <ll, ll>
#define veci vector <int>
#define vecll vector <ll>

const int dx[4] = {1, -1, 0, 0};
const int dy[4] = {0, 0, -1, 1};
const double PI = 3.1415926535897932384626433832795;
const double eps = 1e-9;
const int MOD1 = 1e9 + 7;
const int MOD2 = 998244353;

const int MAXN = 1e6 + 10;
int pw[MAXN];

void solve() {
    int n;
    ll k;
    cin >> n >> k;
    pw[0] = 1;
    for(int i = 1; i <= n; ++i) pw[i] = pw[i - 1] * 2ll % MOD1;
    int ans = 1;
    while(n) {
        if(k & 1) k = (k + 1) / 2;
        else {
            k /= 2;
            ans = (ans + pw[n - 1]) % MOD1;
        }
        --n;
    }
    cout << ans;
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int CNT_TESTS = 1;
    ///cin >> CNT_TESTS;
    for(int NUMCASE = 1; NUMCASE <= CNT_TESTS; ++NUMCASE) {
        solve();
        if(NUMCASE != CNT_TESTS) cout << '\n';
    }
    return 0;
}

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