AC automata Template (array + pointer) Hdu2222__ac automatic machine

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Keywords Search Time limit:2000/1000 MS (java/others) Memory limit:65536/32768 K (java/others) Total submission (s): 34852 accepted Submission (s): 11219 Problem Description in the modern time, Search engine came to the life of everybody like Google, Baidu, etc. Wiskey also wants to bring this feature to his image retrieval system. Every image have a long description, when the users type some keywords to find the image, the system would match the keywords W ITH description of the image which the most keywords be matched. To simplify the problem, giving your a description of image, and some keywords, you should tell me how many keywords'll b E match. Input the contain one integer means how many cases'll follow by. Each case would contain two integers n means the number of keywords and n keywords follow. (N <= 10000) Each keyword'll only contains characters ' a '-' Z ', and the length is not longer than 50. The last line is the description, and the length won't be longer than 1000000. Output Print How many keywords are contained in the description. Sample Input 1 5 She he say shr her yasherhs Sample Output 3

I finally moved to AC automaton today.

The original look at the time to remember a bit laborious, have forgotten almost. Today I found some great God's blog, finally understood

This question is basically a template problem, the last array is reference Liu Rugia Training guide, plus this is not faster than one times, he said along the mismatch pointer to the first word node encountered the number

#include <iostream> #include <cstdio> #include <string> #include <cstring> #include <vector > #include <cmath> #include <queue> #include <stack> #include <map> #include <set>
Include<algorithm> using namespace std;
const int maxn=1000010;
const int maxm=50*10010;
const int sigma_size=26;
int n;

Char T[60],S[MAXN];
    struct AC {int ch[maxm][26];
    int VAL[MAXM];
    int FAIL[MAXM],LAST[MAXM];
    int sz;
    void Clear () {memset (ch[0],0,sizeof (ch[0])); sz=1;}
    int idx (char x) {return x ' a ';}
        void Insert (char *s) {int u=0;
        int N=strlen (s);
            for (int i=0;i<n;i++) {int c=idx (s[i]);
                if (!ch[u][c]) {memset (ch[sz],0,sizeof (Ch[sz)));
                val[sz]=0;
            ch[u][c]=sz++;
        } U=ch[u][c];
    } val[u]++;
        } void Getfail () {queue<int> q;
       fail[0]=0; int u=0;
            for (int i=0;i<sigma_size;i++) {u=ch[0][i];
        if (u) {q.push (U); fail[u]=0;last[u]=0}
            while (!q.empty ()) {int R=q.front (); Q.pop ();
                for (int i=0;i<sigma_size;i++) {u=ch[r][i];
                if (!u) {ch[r][i]=ch[fail[r]][i];continue;}
                Q.push (U);
                int V=fail[r];
                while (V&&!ch[v][i]) v=fail[v];
                Fail[u]=ch[v][i];
            Last[u]=val[fail[u]]?fail[u]:last[fail[u]];
        int find (char *s) {int u=0,cnt=0;
        int N=strlen (s);
            for (int i=0;i<n;i++) {int c=idx (s[i]);
            U=CH[U][C];
            The int temp=0;//must have an initial value of 0, which means that while the following two judgments are not valid, while the IF (Val[u]) Temp=u can be performed normally;
            else if (Last[u]) temp=last[u]; while (temp) {Cnt+=val[Temp];
                val[temp]=0;
            TEMP=LAST[TEMP];
    } return CNT;
}}tree;
    int main () {int T;
    scanf ("%d", &t);
        while (t--) {scanf ("%d", &n);
        Tree.clear ();
            for (int i=1;i<=n;i++) {scanf ("%s", T);
        Tree.insert (t);
        } tree.getfail ();
        scanf ("%s", s);
        int Ans=tree.find (s);
    printf ("%d\n", ans);
return 0;
 }

Pointer version:

#include <iostream> #include <cstdio> #include <string> #include <cstring> #include <vector > #include <cmath> #include <queue> #include <stack> #include <map> #include <set>
Include<algorithm> using namespace std;
const int maxn=1000010;
const int maxm=50*10010;
const int sigma_size=26;
int n;
Char T[60],S[MAXN];
    struct Node {int val;
    Node *next[26];
    Node *fail;
    Node *last;
Node () {memset (next,null,sizeof (next)); fail=null;last=null;val=0;};
    struct AC {node *root;
    void Clear () {root=new node ();}
    int idx (char x) {return x ' a ';}
        void Insert (char *s) {int N=strlen (s);
        Node *p=root;
            for (int i=0;i<n;i++) {int c=idx (s[i]);
            if (!p->next[c]) p->next[c]=new node ();
        p=p->next[c];
    } p->val++;
        } void Getfail () {queue<node *> q;
        Node *p=null; Forint c=0;c<sigma_size;c++) {p=root->next[c];
                if (p!=null) {p->fail=p->last=root;
            Q.push (P);
            } while (!q.empty ()) {node *r=q.front (); Q.pop ();
                for (int c=0;c<sigma_size;c++) {p=r->next[c];
                if (p==null) {r->next[c]=r->fail->next[c];continue;}
                Node *v=r->fail;
                while (v&&v->next[c]==null) {V=v->fail}
                if (v==null) p->fail=root;//add Judge else p->fail=v->next[c];
                if (p->fail->val) p->last=p->fail;
                else p->last=p->fail->last;
            Q.push (P);
        "}" int find (char *s) {int N=strlen (s);
        Node *p=root;
        int cnt=0;
            for (int i=0;i<n;i++) {int c=idx (s[i]); p=p->next[c];
            if (!p) p=root;//here must be judged, go along the mismatch edge to root, indicating that there is no such a match, to start from the root node *temp=null;
            if (p->val) temp=p;
            else temp=p->last;
                while (temp!=root&&temp!=null) {cnt+=temp->val;
                temp->val=0;
            temp=temp->last;
    } return CNT;
}}tree;
    int main () {int T;
    scanf ("%d", &t);
        while (t--) {scanf ("%d", &n);
        Tree.clear ();
            for (int i=1;i<=n;i++) {scanf ("%s", T);
        Tree.insert (t);
        } tree.getfail ();
        scanf ("%s", s);
        int Ans=tree.find (s);
    printf ("%d\n", ans);
return 0;
 }