HDU 2896 病毒侵袭 Trie图

标签：hdu   ac自动机   trie图   不加npe系列   

题目大意：给一些病毒字符串，问一些网址中有哪些病毒。

思路：AC自动机挺裸的题，但是听说Trie图还好写，时间还快，以后就不写AC自动机了，直接啥题都上Trie图吧。

注意：此题输出结尾要加回车，否则会PE！

CODE：

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

struct Trie{
    Trie *son[130],*fail;
    int id;
    
    Trie() {
        id = 0;
        memset(son,NULL,sizeof(son));
    }
}*root = new Trie();

int cnt,asks;
char s[10010];
bool v[1010];
int ill[1010];

inline void Insert(char *s,int p)
{
    Trie *now = root;
    while(*s != '\0') {
        if(now->son[*s] == NULL)
            now->son[*s] = new Trie();
        now = now->son[*s];
        ++s;
    }
    now->id = p;
}

void MakeTrieGraph()
{
    static queue<Trie *> q;
    while(!q.empty())    q.pop();
    for(int i = 0; i < 128; ++i)
        if(root->son[i] != NULL)
            root->son[i]->fail = root,q.push(root->son[i]);
    while(!q.empty()) {
        Trie *now = q.front(); q.pop();
        for(int i = 0; i < 128; ++i)
            if(now->son[i] != NULL) {
                Trie *temp = now->fail;
                while(temp != root && temp->son[i] == NULL)
                    temp = temp->fail;
                if(temp->son[i] != NULL)
                    temp = temp->son[i];
                now->son[i]->fail = temp;
                q.push(now->son[i]);
            }
            else    now->son[i] = now->fail->son[i] ? now->fail->son[i]:root;
    }
}

inline void Ask(char *s)
{
    Trie *now = root;
    while(*s != '\0') {
        if(now->son[*s] != NULL)
            now = now->son[*s];
        for(Trie *temp = now; temp != root; temp = temp->fail)
            if(temp->id && !v[temp->id])
                v[temp->id] = true,ill[++ill[0]] = temp->id;
        ++s;
    }
}

int main()
{
    cin >> cnt;
    for(int i = 1; i <= cnt; ++i) {
        scanf("%s",s);
        Insert(s,i);
    }
    MakeTrieGraph();
    cin >> asks;
    int ans = 0;
    for(int i = 1; i <= asks; ++i) {
        memset(v,false,sizeof(v));
        memset(ill,0,sizeof(ill));
        scanf("%s",s);
        Ask(s);
        if(ill[0]) {
            ++ans;
            sort(ill + 1,ill + ill[0] + 1);
            printf("web %d:",i);
            for(int j = 1; j <= ill[0]; ++j)
                printf(" %d",ill[j]);
            puts("");
        }
    }
    printf("total: %d\n",ans);
    return 0;
}

HDU 2896 病毒侵袭 Trie图

标签：hdu   ac自动机   trie图   不加npe系列   

原文地址：http://blog.csdn.net/jiangyuze831/article/details/41542741