AC自动机算法学习

KMP+TRIE

int val[1000100][31],tot;
int tr[1000100];
int fail[1000100];
struct AC_Trie{
	void clean(){
		tot=0;
		memset(val,0,sizeof(val));
		memset(tr,0,sizeof(tr));
		memset(fail,0,sizeof(fail));
	}
	void build(){
		queue<int> q;
		memset(fail,0,sizeof(fail));
		while(!q.empty()) q.pop();
		for(int i=0;i<26;i++) if(val[0][i]!=0) q.push(val[0][i]);
		while(!q.empty()){
			int u=q.front();q.pop();
			for(int i=0;i<26;i++){
				if(val[u][i]!=0){
					fail[val[u][i]]=val[fail[u]][i];
					q.push(val[u][i]); 
				}else{
					val[u][i]=val[fail[u]][i];
				}
			}
		}
	}
	void insert(string x){
		int len=x.length(),p=0;
		for(int i=0;i<len;i++){
			int c=x[i]-'a';
			if(val[p][c]==0) tot++,val[p][c]=tot;
			p=val[p][c];
		}
		tr[p]++;
	}
	int find(string x){
		int len=x.length(),p=0,res=0;
		for(int i=0;i<len;i++){
			p=val[p][x[i]-'a'];
			for(int j=p;j&&~tr[j];j=fail[j]) res+=tr[j],tr[j]=-1;
		}
		return res;
	}
}tree;