#include <bits/stdc++.h>
using namespace std;
#define m_p make_pair
#define all(x) (x).begin(),(x).end()
#define sz(x) ((int)(x).size())
#define fi first
#define se second
typedef long long ll;
mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());
mt19937 rnf(2106);
const int N = 1000006, M = 1000000007;
int ast[N];
void solv()
{
ll n, k;
cin >> n >> k;
ast[0] = 1;
for (int i = 1; i <= n; ++i)
ast[i] = (ast[i - 1] * 2) % M;
if (k == 1)
{
cout << "1\n";
return;
}
if (k == 2)
{
cout << (ast[n - 1] + 1) % M << "\n";
return;
}
for (int i = 1; ; ++i)
{
if (k > (1LL << i) && k <= (1LL << (i + 1)))
{
k -= (1LL << i);
int ans = 0;
for (int j = 0; ; ++j)
{
if (k == 1)
{
ans = (ans + 1) % M;
break;
}
if (k % 2 == 0)
{
ans = (ans + ast[n - j - 1]) % M;
k /= 2;
}
else
{
k /= 2;
++k;
}
}
ans = (ans + ast[n - i - 1]) % M;
cout << ans << "\n";
break;
}
}
}
int main()
{
#ifdef SOMETHING
freopen("input.txt", "r", stdin);
//freopen("output.txt", "w", stdout);
#endif // SOMETHING
ios_base::sync_with_stdio(false), cin.tie(0);
int tt = 1;
//cin >> tt;
while (tt--)
{
solv();
}
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
332 KB |
Output is correct |
2 |
Correct |
0 ms |
332 KB |
Output is correct |
3 |
Correct |
1 ms |
204 KB |
Output is correct |
4 |
Correct |
1 ms |
204 KB |
Output is correct |
5 |
Correct |
1 ms |
204 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
332 KB |
Output is correct |
2 |
Correct |
0 ms |
332 KB |
Output is correct |
3 |
Correct |
1 ms |
204 KB |
Output is correct |
4 |
Correct |
1 ms |
204 KB |
Output is correct |
5 |
Correct |
1 ms |
204 KB |
Output is correct |
6 |
Correct |
1 ms |
332 KB |
Output is correct |
7 |
Correct |
0 ms |
328 KB |
Output is correct |
8 |
Correct |
1 ms |
332 KB |
Output is correct |
9 |
Correct |
1 ms |
204 KB |
Output is correct |
10 |
Correct |
1 ms |
204 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
332 KB |
Output is correct |
2 |
Correct |
0 ms |
332 KB |
Output is correct |
3 |
Correct |
1 ms |
204 KB |
Output is correct |
4 |
Correct |
1 ms |
204 KB |
Output is correct |
5 |
Correct |
1 ms |
204 KB |
Output is correct |
6 |
Correct |
1 ms |
332 KB |
Output is correct |
7 |
Correct |
0 ms |
328 KB |
Output is correct |
8 |
Correct |
1 ms |
332 KB |
Output is correct |
9 |
Correct |
1 ms |
204 KB |
Output is correct |
10 |
Correct |
1 ms |
204 KB |
Output is correct |
11 |
Correct |
1 ms |
332 KB |
Output is correct |
12 |
Correct |
1 ms |
332 KB |
Output is correct |
13 |
Correct |
1 ms |
332 KB |
Output is correct |
14 |
Correct |
1 ms |
460 KB |
Output is correct |
15 |
Correct |
6 ms |
4044 KB |
Output is correct |