QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#619558 | #8339. Rooted Tree | lzy | WA | 0ms | 3708kb | C++14 | 669b | 2024-10-07 14:39:33 | 2024-10-07 14:39:34 |
Judging History
answer
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
int mod=1e9+9;
ll qpow(ll a,ll b){
ll res=1;
a%=mod;
while(b){
if(b&1)res=res*a%mod;
a=a*a%mod;
b>>=1;
}
return res;
}
int main() {
ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
ll n,k;
cin>>n>>k;
ll av;
ll sum=0,leave=0,siz1=1,siz2=1;
for(int i=1;i<=k;i++){
av=leave*qpow(siz2,mod-2)%mod;
sum=(sum+(av+1)%mod)%mod;
leave=(leave+(av+1)%mod-av+mod)%mod;
siz1=(siz1+n)%mod;
siz2=(siz2+n-1)%mod;
}
sum*=n;
sum%=mod;
cout<<sum<<"\n";
return 0;
}
Details
Tip: Click on the bar to expand more detailed information
Test #1:
score: 0
Wrong Answer
time: 0ms
memory: 3708kb
input:
6 2
output:
13
result:
wrong answer 1st numbers differ - expected: '18', found: '13'