Submission #399607

#	Time	Username	Problem	Language	Result	Execution time	Memory
399607		cadmiumsky	Rack (eJOI19_rack)	C++14	40 / 100	9 ms	8128 KiB

rack

#include <iostream>
#define mod 1000000007
#define int long long


using namespace std;

int p2[1000001];

int n;

static int getnum(int poz, int step, int val=0) {
  if(step==n)
    return val;
  int len=p2[n-step-1];
  if(poz>=len) {
    val=(val+p2[step])%mod;
    poz-=len;
  }
  return getnum(poz,step+1,val);
}

signed main() {
  p2[0]=1;
  for(int i=1; i<=1000000; i++)
    p2[i]=((long long)p2[i-1]*2LL)%mod;
  int k;
  cin >> n >> k;
  cout << 1+getnum(k-1,0) <<'\n';
  return 0;
}

• Subtask 1: 20 / 20
• Subtask 2: 20 / 20
• Subtask 3: 0 / 60