【HDOJ】2896 病毒侵袭

AC自动机模板题。

#include <iostream>
#include <cstdio>
#include <cstring>
#include <queue>
using namespace std;

#define TRIEN 128
#define MAXN  505

typedef struct Trie {
    int in;
    Trie *fail;
    Trie *next[TRIEN];
    Trie() {
        in = 0;
        fail = NULL;
        memset(next, 0, sizeof(next));
    }
} Trie;

Trie *root;
char src[205], des[10005];
bool visit[MAXN];

void create(char str[], int in) {
    int i = 0, id;
    Trie *p = root, *q;

    while (str[i]) {
        id = str[i];
        ++i;
        if (p->next[id] == NULL) {
            q = new Trie();
            p->next[id] = q;
        }
        p = p->next[id];
    }
    p->in = in;
}

void build_fail() {
    int i;
    Trie *p, *q;
    queue<Trie *> que;

    for (i=0; i<TRIEN; ++i) {
        if (root->next[i]) {
            root->next[i]->fail = root;
            que.push(root->next[i]);
        }
    }

    while (!que.empty()) {
        p = que.front();
        que.pop();
        for (i=0; i<TRIEN; ++i) {
            if (p->next[i]) {
                q = p->fail;
                while (q != NULL) {
                    if (q->next[i]) {
                        p->next[i]->fail = q->next[i];
                        break;
                    }
                    q = q->fail;
                }
                if (q == NULL)
                    p->next[i]->fail = root;
                que.push(p->next[i]);
            }
        }
    }
}

void search() {
    int i = 0, id;
    Trie *p = root, *tmp;

    while (des[i]) {
        id = des[i];
        ++i;
        while (p->next[id]==NULL && p!=root)
            p = p->fail;
        p = p->next[id];
        if (p == NULL)
            p = root;
        tmp = p;
        while (tmp != root) {
            visit[tmp->in] = true;
            tmp = tmp->fail;
        }
    }
}

void del(Trie *t) {
    if (t == NULL)
        return ;
    for (int i=0; i<TRIEN; ++i)
        del(t->next[i]);
    delete t;
}

int main() {
    int n, m, cnt, total;
    int i;

    while (scanf("%d",&n) != EOF) {
        root = new Trie();
        for (i=1; i<=n; ++i) {
            scanf("%s", src);
            create(src, i);
        }
        build_fail();
        scanf("%d", &m);
        total = 0;
        for (i=1; i<=m; ++i) {
            scanf("%s", des);
            memset(visit, false, sizeof(visit));
            search();
            cnt = 0;
            for (int j=1; j<=n; ++j) {
                if (visit[j]) {
                    if (!cnt)
                        printf("web %d:", i);
                    ++cnt;
                    printf(" %d", j);
                }
            }
            if (cnt) {
                printf("
");
                ++total;
            }
        }
        printf("total: %d
", total);
        del(root);
    }

    return 0;
}