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QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#190458 | #6137. Sub-cycle Graph | Zhou_JK | WA | 167ms | 5200kb | C++23 | 1.4kb | 2023-09-28 21:57:13 | 2023-09-28 21:57:14 |
Judging History
answer
#include<iostream>
#include<cstdio>
using namespace std;
const int N=100005;
const int MOD=1000000007;
const int INV2=500000004;
int qpow(int a,int b)
{
int res=1;
while(b)
{
if(b&1) res=(long long)res*a%MOD;
a=(long long)a*a%MOD,b>>=1;
}
return res;
}
int getinv(int a)
{
return qpow(a,MOD-2);
}
int fac[N+N],ifac[N+N];
void init(int n=200000)
{
fac[0]=1;
for(int i=1;i<=n;i++)
fac[i]=(long long)fac[i-1]*i%MOD;
ifac[n]=qpow(fac[n],MOD-2);
for(int i=n;i>=1;i--)
ifac[i-1]=(long long)ifac[i]*i%MOD;
return;
}
int C(int n,int m)
{
if(m>n) return 0;
if(m==0||m==n) return 1;
return (long long)fac[n]*ifac[m]%MOD*ifac[n-m]%MOD;
}
int n;
long long m;
void solve()
{
cin>>n>>m;
if(m>n) cout<<0<<"\n";
else if(m==n)
{
int ans=(long long)fac[n-1]*INV2%MOD;
cout<<ans<<"\n";
}
else
{
int ans=0;
int pre=1;
for(int i=1;i<=n-m;i++)
{
pre=(long long)pre*(2*i-1)%MOD;
ans=(ans+(long long)C(n,n-m-i)*fac[m-i]%MOD*C(m-1,i-1)%MOD*C(m+i,2*i)%MOD*pre)%MOD;
}
cout<<ans<<"\n";
}
return;
}
int main()
{
ios::sync_with_stdio(false);
cin.tie(nullptr),cout.tie(nullptr);
init();
int T;
cin>>T;
while(T--)
solve();
return 0;
}
Details
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Test #1:
score: 100
Accepted
time: 3ms
memory: 5180kb
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: 167ms
memory: 5200kb
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:
0 3 3 1 0 6 15 12 3 0 10 45 90 60 12 0 15 105 375 630 360 60 0 21 210 1155 3465 5040 2520 360 0 28 378 2940 13545 35280 45360 20160 2520 0 36 630 6552 42525 170100 393120 453600 181440 20160 0 45 990 13230 114345 643545 2286900 4762800 4989600 1814400 181440 0 55 1485 24750 273735 2047815 10239075 3...
result:
wrong answer 1st numbers differ - expected: '1', found: '0'