HDU 4117

HDU - 4117

构建AC自动机

dp从每一个的子串上转移过来

转移过程中不断匹配，然后统计\(fail\)树上前缀的最大值，这是一个动态的过程

于是我们用树剖线段树动态维护

const int N=2e4+10,SIZE=2.3e5+10;

bool be;
int n,m;
string s[N];

int End[N],val[N];
int trie[SIZE][26],fail[SIZE],cnt;
void clear(){
	memset(trie,0,sizeof (int) * (cnt+1)*26);
	cnt=0;
}

int Insert(string &s){
	int p=0;
	rep(i,0,s.size()-1) {
		//if(!isalpha(s[i])) while(1);
		int x=s[i]-'a';
		if(!trie[p][x]) trie[p][x]=++cnt;
		p=trie[p][x];
	}
	return p;
}

int sz[SIZE],son[SIZE],top[SIZE],fa[SIZE];

struct Edge{
	int to,nxt;
}e[SIZE];
int head[SIZE],ecnt;
void AddEdge(int u,int v){
	e[++ecnt].to=v;
	e[ecnt].nxt=head[u];
	head[u]=ecnt;
}




void dfs1(int u){
	sz[u]=1,son[u]=-1;
	for(int i=head[u];i;i=e[i].nxt){
		int v=e[i].to;
		if(!v) continue;
		fa[v]=u;
		dfs1(v);
		sz[u]+=sz[v];
		if(son[u]==-1||sz[v]>sz[son[u]]) son[u]=v;
	}
}

int L[SIZE],R[SIZE],dfn;
//id[SIZE];
void dfs2(int u,int t){
	top[u]=t;
	L[u]=++dfn;
	if(~son[u]) dfs2(son[u],t);
	for(int i=head[u];i;i=e[i].nxt){
		int v=e[i].to;
		if(!v||v==son[u]) continue;
		dfs2(v,v);
	}
	R[u]=dfn;
}

void chk(int &a,int b){ ((a<b)&&(a=b)); }
struct SGT{
	int sum[SIZE<<2];
	void clear() { memset(sum,0,sizeof sum); }
	void Upd(int p,int l,int r,int x,int y){
		chk(sum[p],y);
		if(l==r) return;
		int mid=(l+r)>>1;
		if(x<=mid) Upd(p<<1,l,mid,x,y);
		else Upd(p<<1|1,mid+1,r,x,y);
	}
	int Que(int p,int l,int r,int ql,int qr){
		if(l==ql&&r==qr) return sum[p];
		int mid=(l+r)>>1;
		if(qr<=mid) return Que(p<<1,l,mid,ql,qr);
		else if(ql>mid) return Que(p<<1|1,mid+1,r,ql,qr);
		else return max(Que(p<<1,l,mid,ql,mid),Que(p<<1|1,mid+1,r,mid+1,qr));
	}
}tr;


void Build(){
	static queue <int> que;
	dfn=0;
	memset(head,0,sizeof head);ecnt=0;
	rep(i,0,25) if(trie[0][i]) {
		que.push(trie[0][i]);
		fail[trie[0][i]]=0;
	}
	while(!que.empty()){
		int u=que.front(); que.pop();
		AddEdge(fail[u],u);
		rep(i,0,25) {
			int &v=trie[u][i];
			if(v) {
				que.push(v);
				fail[v]=trie[fail[u]][i];
			} else v=trie[fail[u]][i];
		}
	}
	fa[0]=-1,dfs1(0);dfs2(0,0);
}


bool ed;

int main(){
	//cout<<&ed-&be<<endl;
	ios::sync_with_stdio(false);
	int T; cin>>T;
	rep(kase,1,T) {
		clear();
		tr.clear();
		cin>>n;
		rep(i,1,n) {
			cin>>s[i]>>val[i];
			End[i]=Insert(s[i]);
		}
		Build();
		int ans=0;
		rep(i,1,n) {
			int res=0,p=0;
			rep(j,0,s[i].size()-1) {
				p=trie[p][s[i][j]-'a'];
				int x=p;
				while(~x) {
					chk(res,tr.Que(1,1,dfn,L[top[x]],L[x]));
					x=fa[top[x]];
				}
			}
			chk(res,res+val[i]);
			tr.Upd(1,1,dfn,L[End[i]],res);
			chk(ans,res);
			string t;swap(t,s[i]);
		}
		printf("Case #%d: %d\n",kase,ans);
	}
}