hdu 2222 Keywords Search （AC自动机～）

来源：互联网发布：java转json忽略字段编辑：程序博客网时间：2024/06/04 19:22

看了两天模板了。。。

其实我还是懵逼的，啊啊啊。有毒。。。

背个模板先

#include <stdio.h>#include <string.h>#include <iostream>#include <queue>#include <string>using namespace std;const int MAX_N = 26;const int MAX_NODE = 500010;struct NODE {    int cnt;    NODE *next[MAX_N], *fail;    NODE() {        cnt = 0;        fail = NULL;        memset(next, 0, sizeof(next));    }};NODE *head;void Build_trie(char *s, NODE *head) {    int len = strlen(s);    for (int i = 0; i < len; i++) {        int k = s[i] - 'a';        if (head->next[k] == NULL) head->next[k] = new NODE();        head = head->next[k];    }    head->cnt++;}queue<NODE *> q;void Build_fail(NODE *head) {    head->fail = NULL;    q.push(head);    while (!q.empty()) {        NODE *now = q.front();        q.pop();        for (int i = 0; i < MAX_N; i++)            if (now->next[i]) {                NODE *p = now->fail;                while (p) {                    if (p->next[i]) {                        now->next[i]->fail = p->next[i];                        break;                    }                    p = p->fail;                }                if (p == NULL) now->next[i]->fail = head;                q.push(now->next[i]);            }    }}int AC_find(NODE *head, char *s) {    int len = strlen(s), sum = 0;    NODE *p = head;    for (int i = 0; i < len; i++) {        int k = s[i] - 'a';        while (p->next[k] == NULL && p != head) p = p->fail;        p = p->next[k] == NULL ? head : p->next[k];        NODE *tmp = p;        while (tmp != head && tmp->cnt != -1) {            sum += tmp->cnt;            tmp->cnt = -1;            tmp = tmp->fail;        }    }    return sum;}char s[1000005];char ss[100];int main() {    int n, ncases;    scanf("%d", &ncases);    while (ncases--) {        head = new NODE();        scanf("%d", &n);        while (n--) {            scanf("%s", ss);            Build_trie(ss, head);        }        Build_fail(head);        scanf("%s", s);        int sum = AC_find(head, s);        printf("%d\n", sum);    }    return 0;}

阅读全文

0 0