HDU 2222 AC自动机 入门题

题目链接

第一次写AC自动机……

代码如下：

#include <cstdio>#include <iostream>#include <cstring>#include <queue>#define sf scanf#define pf printfusing namespace std;const int sigma_size = 26;struct Trie_Node{    int value;//单词节点计数 其他为0    struct Trie_Node* next[sigma_size];    struct Trie_Node* fail;//失配跳转指针  没有最大前后缀则为root    char ch;};typedef struct Trie_Node* poi_node;poi_node root;poi_node make_node(char ch){    poi_node node = new Trie_Node;    node -> value = 0;    node -> fail = NULL;    node -> ch = ch;    for(int i = 0;i < sigma_size;++i){        node -> next[i] = NULL;    }    return node;}void Insert(char* s){    int len = strlen(s);    poi_node cur = root;    for(int i = 0;i < len;++i){        int idx = s[i] - 'a';        if(cur -> next[idx] == NULL){            cur -> next[idx] = make_node(idx + 'a');        }        cur = cur -> next[idx];    }    cur -> value++;    return;}void get_fail(){    queue<poi_node> q;    q.push(root);    while( !q.empty() ){        poi_node cur = q.front();q.pop();        for(int i = 0;i < sigma_size;++i){            if(cur -> next[i]){                poi_node p = cur -> fail;                while(p && !p -> next[i]) p = p -> fail;                cur -> next[i] -> fail = p ? p -> next[i] : root;                q.push(cur -> next[i]);            }        }    }}int Search(char* s){    int len = strlen(s);    int ans = 0;    poi_node cur = root;    for(int i = 0;i < len;++i){        int idx = s[i] - 'a';        if(cur -> next[idx] == NULL){ //失配            poi_node f = cur;            while(f && !f -> next[idx]){                f = f -> fail;            }            cur = f ? f -> next[idx] : root;        }        else cur = cur -> next[idx];        ans += cur -> value;        if(cur -> value > 0){            cur -> value = 0;            poi_node p = cur -> fail;            while(p){                ans += p -> value;                p -> value = 0;                p = p -> fail;            }        }    }    return ans;}void DFS(poi_node ROOT){    for(int i = 0;i < sigma_size;++i){        if(ROOT -> next[i] != NULL) DFS(ROOT->next[i]);    }    delete ROOT;}char word[60];char line[1000000 + 5];int main(){    int T;    sf("%d",&T);    while(T--){        root = make_node('#');        int n;sf("%d",&n);        for(int i = 0;i < n;++i){            sf("%s",word);            Insert(word);        }        sf("%s",line);        get_fail();        pf("%d\n",Search(line));        DFS(root);    }    return 0;}