|
|
|
|
|
|
|
|
|
|
| #include <algorithm>
|
| #include <functional>
|
| #include <numeric>
|
| #include <iostream>
|
| #include <iomanip>
|
| #include <cstdio>
|
| #include <cmath>
|
| #include <complex>
|
| #include <cstdlib>
|
| #include <ctime>
|
| #include <cstring>
|
| #include <cassert>
|
| #include <string>
|
| #include <vector>
|
| #include <list>
|
| #include <map>
|
| #include <set>
|
| #include <deque>
|
| #include <queue>
|
| #include <stack>
|
| #include <bitset>
|
| #include <sstream>
|
| using namespace std;
|
|
|
| #define LL long long
|
| #define LD long double
|
| #define PR pair<int,int>
|
|
|
| #define Fox(i,n) for (i=0; i<n; i++)
|
| #define Fox1(i,n) for (i=1; i<=n; i++)
|
| #define FoxI(i,a,b) for (i=a; i<=b; i++)
|
| #define FoxR(i,n) for (i=(n)-1; i>=0; i--)
|
| #define FoxR1(i,n) for (i=n; i>0; i--)
|
| #define FoxRI(i,a,b) for (i=b; i>=a; i--)
|
| #define Foxen(i,s) for (i=s.begin(); i!=s.end(); i++)
|
| #define Min(a,b) a=min(a,b)
|
| #define Max(a,b) a=max(a,b)
|
| #define Sz(s) int((s).size())
|
| #define All(s) (s).begin(),(s).end()
|
| #define Fill(s,v) memset(s,v,sizeof(s))
|
| #define pb push_back
|
| #define mp make_pair
|
| #define x first
|
| #define y second
|
|
|
| template<typename T> T Abs(T x) { return(x<0 ? -x : x); }
|
| template<typename T> T Sqr(T x) { return(x*x); }
|
|
|
| const int INF = (int)1e9;
|
| const LD EPS = 1e-12;
|
| const LD PI = acos(-1.0);
|
|
|
| bool Read(int &x)
|
| {
|
| char c,r=0,n=0;
|
| x=0;
|
| for(;;)
|
| {
|
| c=getchar();
|
| if ((c<0) && (!r))
|
| return(0);
|
| if ((c=='-') && (!r))
|
| n=1;
|
| else
|
| if ((c>='0') && (c<='9'))
|
| x=x*10+c-'0',r=1;
|
| else
|
| if (r)
|
| break;
|
| }
|
| if (n)
|
| x=-x;
|
| return(1);
|
| }
|
|
|
| #define MOD 1000000007
|
|
|
| int fact[2005],ifact[2005];
|
|
|
| PR GCD(int a,int b)
|
| {
|
| if (!b)
|
| return(mp(1,0));
|
| PR p=GCD(b,a%b);
|
| return(mp(p.y,p.x-p.y*(a/b)));
|
| }
|
|
|
| int Add(int a,int b)
|
| {
|
| a+=b;
|
| if (a>=MOD)
|
| a-=MOD;
|
| return(a);
|
| }
|
|
|
| int Mult(int a,int b)
|
| {
|
| return((LL)a*b%MOD);
|
| }
|
|
|
| int Div(int a,int b)
|
| {
|
| b=GCD(b,MOD).x;
|
| if (b<0)
|
| b+=MOD;
|
| return(Mult(a,b));
|
| }
|
|
|
| int Ch(int n,int k)
|
| {
|
| if ((k<0) || (k>n))
|
| return(0);
|
| Min(k,n-k);
|
| int i,v=1;
|
| Fox(i,k)
|
| v=Mult(v,n-i);
|
| return(Mult(v,ifact[k]));
|
| }
|
|
|
| int main()
|
| {
|
| int T,t;
|
| int N,M;
|
| int i,j,s;
|
| int ans;
|
| int R[2000],cnt[4001];
|
| Fox(i,2005)
|
| {
|
| fact[i]=i ? Mult(fact[i-1],i) : 1;
|
| ifact[i]=Div(1,fact[i]);
|
| }
|
| Read(T);
|
| Fox1(t,T)
|
| {
|
| s=ans=0;
|
| Read(N),Read(M);
|
| Fox(i,N)
|
| Read(R[i]),s+=R[i]*2;
|
| if (N==1)
|
| {
|
| ans=M;
|
| goto Done;
|
| }
|
| Fill(cnt,0);
|
| Fox(i,N)
|
| Fox(j,N)
|
| if (i!=j)
|
| cnt[R[i]+R[j]]++;
|
| Fox1(i,4000)
|
| if (cnt[i])
|
| ans=Add(ans,Mult(cnt[i],Mult(fact[N-2],Ch(M+i-s+N-1,N))));
|
| Done:;
|
| printf("Case #%d: %d\n",t,ans);
|
| }
|
| return(0);
|
| } |
