#include <iostream>
#include <map>
#include <unordered_map>
#include <set>
#include <vector>
#include <queue>
#include <algorithm>
#include <cmath>
#include <iomanip>
using namespace std;
#define ll long long
#define PLL pair<ll, ll>
#define PB push_back
#define F first
#define S second
#define MP make_pair
const ll INF = 999999999999999999;
const ll M = 1000000000+7;
ll binExp(ll a, ll b){
if(a==1){
return 1;
}
if(b==0){
return 1;
}
ll ans = 1;
if(b%2==1){
ans = a;
}
return (binExp((a*a)%M,b/2)*ans)%M;
}
int main(){
ll n,k;
cin>>n>>k;
ll index = 1,npow = 1,tpow = 1, m = binExp(2,n),Inv = binExp(2,M-2);
k--;
for(ll i=0; i<=n; i++){
if(npow>k or npow<1){
break;
}
//cout<<(k&tpow)<<" "<<tpow<<endl;
if((k&npow)!=0){
//cout<<(m/tpow)/2<<endl;
index = (index + (Inv*(m*tpow)%M)%M)%M;
}
tpow = (tpow*Inv)%M;
npow*=2;
}
cout<<index<<endl;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
344 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
344 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
344 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |