bzoj 1079 [SCOI2008]着色方案 dp

#include <bits/stdc++.h>
using namespace std;
#define mod 1000000007
#define ll long long
ll f[16][16][16][16][16][6],num[6];
bool vis[16][16][16][16][16][6];
int n;
ll F(int x1,int x2,int x3,int x4,int x5,int num)
{
if(x1+x2+x3+x4+x5==0)return 1;
ll &t=f[x1][x2][x3][x4][x5][num];
bool &t1=vis[x1][x2][x3][x4][x5][num];
if(t1)return t;
if(x1)t+=(x1-(num==2))*F(x1-1,x2,x3,x4,x5,1);
if(x2)t+=(x2-(num==3))*F(x1+1,x2-1,x3,x4,x5,2);
if(x3)t+=(x3-(num==4))*F(x1,x2+1,x3-1,x4,x5,3);
if(x4)t+=(x4-(num==5))*F(x1,x2,x3+1,x4-1,x5,4);
if(x5)t+=x5*F(x1,x2,x3,x4+1,x5-1,5);
t1=1;return t%=mod;
}
int main()
{
//freopen("tt.in","r",stdin);
scanf("%d",&n);
for(int i=1,x;i<=n;i++)
scanf("%d",&x),num[x]++;
printf("%lld\n",F(num[1],num[2],num[3],num[4],num[5],0));
return 0;
}