[Hash] BZOJ 4337 树的同构

哈希函数 自己乱搞一个就行了

#include
#include
#include
#include
#define cl(x) memset(x,0,sizeof(x))
#define M 13000007
#define V G[p].v
using namespace std;
typedef long long ll;

inline char nc()
{
	static char buf[100000],*p1=buf,*p2=buf;
	if (p1==p2) { p2=(p1=buf)+fread(buf,1,100000,stdin); if (p1==p2) return EOF; }
	return *p1++;
}

inline void read(int &x)
{
	char c=nc(),b=1;
	for (;!(c>='0' && c<='9');c=nc()) if (c=='-') b=-1;
	for (x=0;c>='0' && c<='9';x=x*10+c-'0',c=nc()); x*=b;
}

const int pri[55]={0,2,23,29,37,53,67,73,79,83,89,97,101,103,107,109,113,127,131,137,139,149,151,157,163,167,173,179,181,191,193,197,199,211,223,227,229,
233,239,241,251,257,263,269,271,277,281,283,293,307};

struct edge{
	int u,v;
	int next;
};

edge G[105];
int head[55],num=1;

inline void add(int u,int v,int p)
{
	G[p].u=u; G[p].v=v; G[p].next=head[u]; head[u]=p;
}

int n,m;
int tot[55];
ll data[55];
ll hash[55][55];

inline void dfs(int u,int fa)
{
	data[u]=1;
	ll d[55]={0};
	int pnt=0;
	for (int p=head[u];p;p=G[p].next)
		if (V!=fa)
		{
			dfs(V,u);
			d[++pnt]=data[V];
		}
	sort(d+1,d+pnt+1);
	for (int i=1;i<=pnt;i++)
		(data[u]+=d[i]*pri[i])%=M;
}

int main()
{
	int _v;
	freopen("t.in","r",stdin);
	freopen("t.out","w",stdout);
	read(m);
	for (int t=1;t<=m;t++)
	{
		read(n);
		tot[t]=n;
		cl(G); cl(head); num=1;
		for (int i=1;i<=n;i++)
		{
			read(_v);
			if (_v) add(_v,i,++num),add(i,_v,++num);
		}
		for (int i=1;i<=n;i++)
			dfs(i,0),hash[t][i]=data[i];
		sort(hash[t]+1,hash[t]+tot[t]+1);
		int ans=0;
		for (int i=1;i