Submission #302402

#	Time	Username	Problem	Language	Result	Execution time	Memory
302402		MasterTaster	Rack (eJOI19_rack)	C++14	100 / 100	9 ms	7936 KiB

rack

#include <bits/stdc++.h>

#define pb push_back
#define ll long long
#define pii pair<int, int>
#define xx first
#define yy second
#define MOD 1000000007

using namespace std;

ll n, k, ress;
ll dvaNa[1000010];

int main(){
    ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);

    cin>>n>>k;
    k--;

    dvaNa[0]=1;
    for (int i=1; i<=n+1; i++) dvaNa[i]=(dvaNa[i-1]*2)%MOD;

    int i=0;
    while (k)
    {
        int cif=k%2; k/=2;
        ress=(ress+(cif*(dvaNa[n-1-i])%MOD)%MOD)%MOD;
        i++;
    }

    cout<<(ress+1)%MOD;

}

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