QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#91717 | #6137. Sub-cycle Graph | Liberty12619 | WA | 196ms | 4192kb | C++20 | 1.2kb | 2023-03-29 14:25:31 | 2023-03-29 14:25:33 |
Judging History
answer
#include<bits/stdc++.h>
using namespace std;
const int N = 1e5+10,mod=1e9+7;
typedef long long LL;
int fact[N],infact[N];
int qmi(int a,int b)
{
int res=1;
while(b)
{
if(b&1)res=(LL)res*a%mod;
a=(LL)a*a%mod;
b>>=1;
}
return res;
}
void init()
{
infact[0]=fact[0]=1;
for(int i=1;i<N;i++) fact[i]=(LL)fact[i-1]*i%mod;
infact[N-1]=qmi(fact[N-1],mod-2);
for(int i= N-2;i>0;i--) infact[i]=(LL)infact[i+1]*(i+1)%mod;
}
int C(int a,int b)
{
if(b>a) return 0;
return (LL)fact[a]*infact[b]%mod*infact[a-b]%mod;
}
void solve()
{
int n,m;
cin>>n>>m;
if(m>n)
{
puts("0");
return;
}
if(m==n)
{
cout<<fact[n-1]<<endl;
return ;
}
if(m==0)
{
puts("1");
return ;
}
int t=1,ans=0;
for(int i=1;i<=n-m;i++)
{
t=(LL)t*(2*i-1)%mod;
ans=(ans+(LL)C(n,n-m-i)*C(m+i,2*i)%mod*t%mod
*fact[m-i]%mod*C(m-1,i-1)%mod)%mod;
}
//cout<<infact[2]*2%mod<<endl;
cout<<ans<<endl;
}
int main()
{
int T =1;
cin>>T;
init();
while(T--)
{
solve();
}
return 0;
}
Details
Tip: Click on the bar to expand more detailed information
Test #1:
score: 100
Accepted
time: 2ms
memory: 4192kb
input:
3 4 2 4 3 5 3
output:
15 12 90
result:
ok 3 number(s): "15 12 90"
Test #2:
score: -100
Wrong Answer
time: 196ms
memory: 4192kb
input:
17446 3 0 3 1 3 2 3 3 4 0 4 1 4 2 4 3 4 4 5 0 5 1 5 2 5 3 5 4 5 5 6 0 6 1 6 2 6 3 6 4 6 5 6 6 7 0 7 1 7 2 7 3 7 4 7 5 7 6 7 7 8 0 8 1 8 2 8 3 8 4 8 5 8 6 8 7 8 8 9 0 9 1 9 2 9 3 9 4 9 5 9 6 9 7 9 8 9 9 10 0 10 1 10 2 10 3 10 4 10 5 10 6 10 7 10 8 10 9 10 10 11 0 11 1 11 2 11 3 11 4 11 5 11 6 11 7 11...
output:
1 3 3 2 1 6 15 12 6 1 10 45 90 60 24 1 15 105 375 630 360 120 1 21 210 1155 3465 5040 2520 720 1 28 378 2940 13545 35280 45360 20160 5040 1 36 630 6552 42525 170100 393120 453600 181440 40320 1 45 990 13230 114345 643545 2286900 4762800 4989600 1814400 362880 1 55 1485 24750 273735 2047815 10239075 ...
result:
wrong answer 4th numbers differ - expected: '1', found: '2'