#include<iostream>
#include<vector>
#include<algorithm>
#include<map>
#include<set>
#include<climits>
#include<numeric>
#include<queue>
#include<unordered_map>
#include<unordered_set>
#include<bitset>
#include<string.h>
#include<cmath>
#include<stack>
#define int uint64_t
using namespace std;
const int mod = 1e9 + 7;
int cdiv(int a, int b){
return (a + b - 1ll) / b;
}
int bpow(int a, int b){
if(a == 1 or b == 0)return 1;
if(a == 0)return 0; // watch out for 0^0
int ans = 1;
a %= mod;
while(b > 0){
if(b&1)ans = ans * a % mod;
a = a * a % mod;
b >>= 1;
}
return ans;
}
int inv(int x){
return bpow(x, mod-2);
}
signed main(){
ios_base::sync_with_stdio(false);cin.tie(NULL);
int n, k;
cin >> n >> k;
int ans = 1,
add = bpow(2, n-1),
kcpy = k,
inv2 = inv(2);
while(k > 1){
if(!(k&1))ans += add;
add = add * inv2 % mod;
k = cdiv(k, 2);
}
cout << ans << endl;
}
Compilation message
rack.cpp: In function 'int main()':
rack.cpp:47:9: warning: unused variable 'kcpy' [-Wunused-variable]
47 | kcpy = k,
| ^~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Correct |
1 ms |
212 KB |
Output is correct |
4 |
Correct |
1 ms |
212 KB |
Output is correct |
5 |
Correct |
1 ms |
212 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Correct |
1 ms |
212 KB |
Output is correct |
4 |
Correct |
1 ms |
212 KB |
Output is correct |
5 |
Correct |
1 ms |
212 KB |
Output is correct |
6 |
Correct |
0 ms |
212 KB |
Output is correct |
7 |
Correct |
1 ms |
212 KB |
Output is correct |
8 |
Correct |
1 ms |
320 KB |
Output is correct |
9 |
Correct |
0 ms |
212 KB |
Output is correct |
10 |
Correct |
1 ms |
212 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Correct |
1 ms |
212 KB |
Output is correct |
4 |
Correct |
1 ms |
212 KB |
Output is correct |
5 |
Correct |
1 ms |
212 KB |
Output is correct |
6 |
Correct |
0 ms |
212 KB |
Output is correct |
7 |
Correct |
1 ms |
212 KB |
Output is correct |
8 |
Correct |
1 ms |
320 KB |
Output is correct |
9 |
Correct |
0 ms |
212 KB |
Output is correct |
10 |
Correct |
1 ms |
212 KB |
Output is correct |
11 |
Incorrect |
1 ms |
212 KB |
Output isn't correct |
12 |
Halted |
0 ms |
0 KB |
- |