Submission #623648

#	Time	Username	Problem	Language	Result	Execution time	Memory
623648		froxyy	Rack (eJOI19_rack)	C++14	100 / 100	9 ms	340 KiB

rack

#include <bits/stdc++.h>
using namespace std;
#define fast ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
typedef long long ll;typedef long double ld;typedef pair<int,int> pii;
#define F first
#define S second
#define PB push_back
#define MP make_pair
const ll mod = 1e9+7, N = 2e6+7, M = 2e6+7, INF = INT_MAX/10;
ll powe(ll x, ll y){ x = x%mod, y=y%(mod-1);ll ans = 1;while(y>0){if (y&1){ans = (1ll * x * ans)%mod;}y>>=1;x = (1ll * x * x)%mod;}return ans;}




void solve(){
    ll n, k;
    cin >> n >> k;
    k--;
    ll v = 1;
    for(int i=1; i<=n; i++)
    {
        if(k%2 == 0)
        {
            v = (v*2) % mod;
        }
        else
            v = (v*2 + 1) % mod;
        k /= 2;
    }
    ll pow2 = 1;
    for(int i=1; i<=n; i++)
    {
        pow2 = (pow2*2) % mod;
    }

    cout << (v - pow2 + 1 + mod) % mod << '\n';
}




signed main(){
    fast;
    int t = 1;
    //cin >> t;
    while(t--){
    	solve();
    }
    return 0;
}

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