#include<bits/stdc++.h>
using namespace std;
#define int long long
const int MAX_N = 1e5;
const int mod = 1e9+7;
vector<int> adj[MAX_N];
int pow2[64];
void precalc(){
pow2[0] = 2;
for(int i = 1; i<61; i++){
pow2[i] = (pow2[i-1] * pow2[i-1])%mod;
}
}
int mpow(int p){
int res= 1;
for(int i = 0; i<61; i++){
if((1LL<<i)&p){
res = (res*pow2[i])%mod;
}
}
return res;
}
signed main(){
int n, d;
cin>>n>>d;
for(int i = 0; i<n-1;i++){
int a, b;
cin>>a>>b;
adj[a-1].push_back(b-1);
adj[b-1].push_back(a-1);
}
precalc();
int res= mpow(2*d);
cout<<res<<endl;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
2652 KB |
Output is correct |
2 |
Incorrect |
1 ms |
2652 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
2652 KB |
Output is correct |
2 |
Correct |
1 ms |
2652 KB |
Output is correct |
3 |
Correct |
1 ms |
2652 KB |
Output is correct |
4 |
Correct |
1 ms |
2652 KB |
Output is correct |
5 |
Correct |
1 ms |
2652 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
2648 KB |
Output is correct |
2 |
Incorrect |
1 ms |
2652 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
2648 KB |
Output is correct |
2 |
Incorrect |
1 ms |
2652 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
2648 KB |
Output is correct |
2 |
Incorrect |
1 ms |
2652 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
2648 KB |
Output is correct |
2 |
Incorrect |
1 ms |
2652 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
2648 KB |
Output is correct |
2 |
Incorrect |
1 ms |
2652 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
2652 KB |
Output is correct |
2 |
Incorrect |
1 ms |
2652 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |