AC自动机

简单版

luogu3808

ps.第一次写，不太美观，加强版的好看些

代码

include

include

include

include

include

include

include

define N 1000005

using namespace std;

int n,ans;
int t,c[N][26],flag[N],f[N];
char ch[N];

void insert()
{
int num,rt=0;
for(int i=0;ch[i];i++)
{
num=ch[i]-'a';
if(!c[rt][num]) c[rt][num]=++t;
rt=c[rt][num];
}
flag[rt]++;
}

queue q;
void getfail()
{
for(int i=0;i<26;i++)
if(c[0][i]) q.push(c[0][i]);
while(!q.empty())
{
int u=q.front();q.pop();
for(int i=0;i<26;i++)
{
if(c[u][i]) f[c[u][i]]=c[f[u]][i],q.push(c[u][i]);
else c[u][i]=c[f[u]][i];
}
}
}

int query()
{
int rt=0;
for(int i=0;ch[i];i++)
{
rt=c[rt][ch[i]-'a'];
for(int j=rt;j&&flag[j]!=-1;j=f[j])
{
ans+=flag[j];
flag[j]=-1;
}
}
return ans;
}

int main()
{
scanf("%d",&n);
for(int i=1;i<=n;i++)
{
scanf("%s",ch);
insert();
}
getfail();
scanf("%s",ch);
query();
printf("%d",ans);
return 0;
}

加强版

luogu3796

代码

include

include

include

include

include

include

include

define N 1000005

using namespace std;

int n,t,Max,ans[160];
char ch[160][160],s[N];

struct node
{
int c[N][26],flag[N],f[N];
void clear()
{
memset(c[0],0,sizeof(c[0]));
memset(f,0,sizeof(f));
memset(flag,0,sizeof(flag));
}
void insert(char* x,int id)
{
int num,rt=0;
for(int i=0;x[i];i++)
{
num=x[i]-'a';
if(!c[rt][num]) c[rt][num]=++t;
rt=c[rt][num];
}
flag[rt]=id;
}
void getfail()
{
queue q;
for(int i=0;i<26;i++)
if(c[0][i]) q.push(c[0][i]);
while(!q.empty())
{
int rt=q.front();q.pop();
for(int i=0;i<26;i++)
{
if(c[rt][i]) f[c[rt][i]]=c[f[rt]][i],q.push(c[rt][i]);
else c[rt][i]=c[f[rt]][i];
}
}
}
void query(char* x)
{
int rt=0;
for(int i=0;x[i];i++)
{
rt=c[rt][x[i]-'a'];
for(int t=rt;t;t=f[t])
{
if(flag[t])
{
ans[flag[t]]++;
Max=max(Max,ans[flag[t]]);
}
}
}
}
}AC;

int main()
{
while(1)
{
scanf("%d",&n);Max=0;
if(!n) break;
for(int i=1;i<=n;i++) scanf("%s",ch[i]),AC.insert(ch[i],i);
AC.getfail();
scanf("%s",s);AC.query(s);
printf("%d\n",Max);
for(int i=1;i<=n;i++)
if(ans[i]==Max) printf("%s\n",ch[i]);
AC.clear();
memset(ans,0,sizeof(ans));Max=0;
}
return 0;
}