HDU 2896 病毒侵袭（AC自动机）

标签：ac自动机   hdu   

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=2896

3
aaa
bbb
ccc
2
aaabbbccc
bbaacc

web 1: 1 2 3
total: 1

代码如下：

#include <stdio.h>
#include <algorithm>
#include <iostream>
#include <string.h>
#include <queue>
using namespace std;
int f[520]; //标记当前某个网站是否包含某个病毒
int flag = 0;
struct Trie
{
    int next[500*210][128],fail[500*210],end[500*210];
    int root,L;
    int newnode()
    {
        for(int i = 0; i < 128; i++)
            next[L][i] = -1;
        end[L++] = -1;
        return L-1;
    }
    void init()
    {
        L = 0;
        root = newnode();
    }
    void insert(char buf[], int id)
    {
        int len = strlen(buf);
        int now = root;
        for(int i = 0; i < len; i++)
        {
            if(next[now][buf[i]] == -1)
                next[now][buf[i]] = newnode();
            now = next[now][buf[i]];
        }
        end[now] = id;
    }
    void build()
    {
        queue<int>Q;
        fail[root] = root;
        for(int i = 0; i < 128; i++)
            if(next[root][i] == -1)
                next[root][i] = root;
            else
            {
                fail[next[root][i]] = root;
                Q.push(next[root][i]);
            }
        while(!Q.empty())
        {
            int now = Q.front();
            Q.pop();
            for(int i = 0; i < 128; i++)
                if(next[now][i] == -1)
                    next[now][i] = next[fail[now]][i];
                else
                {
                    fail[next[now][i]]=next[fail[now]][i];
                    Q.push(next[now][i]);
                }
        }
    }
    int query(char buf[], int id)
    {
        int len = strlen(buf);
        int now = root;
        int mark = 0;
        for(int i = 0; i < len; i++)
        {
            now = next[now][buf[i]];
            int temp = now;
            while( temp != root )
            {
                if(end[temp] != -1)
                {
                    f[end[temp]] = 1;
                    mark = 1;
                }
                temp = fail[temp];
            }
        }
        if(!mark)
            return 0;
        return 1;
    }
};
char buf[10010];
Trie ac;
int main()
{
    int n, m;
    while(~scanf("%d",&n))
    {
        ac.init();
        for(int i = 1; i <= n; i++)
        {
            scanf("%s",buf);
            ac.insert(buf, i);
        }
        ac.build();//fail
        int ans = 0;
        scanf("%d",&m);
        for(int i = 1; i <= m; i++)
        {
            memset(f, 0, sizeof(f));
            scanf("%s",buf);
            int flag = ac.query(buf, i);
            if(!flag)
            {
                continue;
            }
            printf("web %d:",i);
            for(int j = 1; j <= n; j++)
            {
                if(f[j])
                {
                    printf(" %d",j);
                }
            }
            printf("\n");
            ans++;
        }
        printf("total: %d\n",ans);
    }
    return 0;
}

HDU 2896 病毒侵袭（AC自动机）

标签：ac自动机   hdu   

原文地址：http://blog.csdn.net/u012860063/article/details/44463397