Kortit II

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
const ll MOD=1000000007;

ll C(ll m,ll n){
	ll res=1;
	for(ll i=1,j=m;i<=m-n;i++,j--){
		res*=j;
		res/=i;
		res%=MOD;
	}
	return res;
}
ll P(ll n,ll m){
	ll res=1;
	for(ll i=n;i>n-m;i--){
		res*=i;
		res%=MOD;
	}
	return res;
}
void M(ll&a,ll b){
	a=a*b%MOD;
}

ll ans=1;
ll base;

vector<ll>EMP;
void dfs(int u,vector<ll>v,ll n,ll a,ll b){
	if(u==n){
		ll ca=0,cb=0;
		for(ll i=0;i<n;i++){
			if(v[i]>i+1)cb++;
			else if(v[i]<i+1)ca++;
		}if(ca==a&&cb==b){
//			for(int i=0;i<n;i++)cout<<v[i]<<" ";
//			cout<<endl;
			base++;
		}
	}
	for(ll i=1;i<=n;i++){
		vector<ll>::iterator it=find(v.begin(),v.end(),i);
		if(it==v.end()){
			v.push_back(i);
			dfs(u+1,v,n,a,b);
			v.pop_back();
		}
	}
}

void query(ll n,ll a,ll b){	
	dfs(0,EMP,n,a,b);
	M(ans,base);M(ans,P(n,n));
	cout<<ans<<endl;
}

int main(){
	ll Q;
	cin>>Q;
	while(Q--){
		ans=1;base=0;
		ll n,a,b;
		cin>>n>>a>>b;
		ll c=a+b;
		ll d=n-c;
		if(c>n){
			cout<<0<<endl;
			continue;
		}
		if(c<n){
			M(ans,C(n,d));
			M(ans,C(c+1,d));
			M(ans,P(d,d));
			n=c;
		}
		query(n,a,b);
	}
	return 0;
}

Test 1

Group: 1, 2, 3, 4, 5

Verdict: WRONG ANSWER

Test 2

Group: 2, 3, 4, 5

Verdict: WRONG ANSWER

Test 3

Group: 3, 4, 5

Verdict: TIME LIMIT EXCEEDED

Test 4

Group: 4, 5

Verdict: TIME LIMIT EXCEEDED

Test 5

Group: 5

Verdict: TIME LIMIT EXCEEDED

Test 6

Group: 5

Verdict: TIME LIMIT EXCEEDED