hnu10104

AC自动机+DFS

#include <cstdio>

#include <queue>

#include <cstring>

using namespace std;



#define D(x) 



const int MAX_LEN = 3 * (1e4) + 10;

const int MAX_NODE_NUM = MAX_LEN;

const int MAX_CHILD_NUM = 2;



struct Trie

{

    int next[MAX_NODE_NUM][MAX_CHILD_NUM];

    int fail[MAX_NODE_NUM];

    int node_cnt;

    bool vis[MAX_NODE_NUM]; //set it to false

    bool virus[MAX_NODE_NUM];

    int root;



    void init()

    {

        node_cnt = 0;

        root = newnode();

        memset(vis, 0, sizeof(vis));

        memset(virus, 0, sizeof(virus));

    }



    int newnode()

    {

        for (int i = 0; i < MAX_CHILD_NUM; i++)

            next[node_cnt][i] = -1;

        virus[node_cnt++] = false;

        return node_cnt - 1;

    }



    int get_id(char a)

    {

        return a - '0';

    }



    void insert(char buf[])

    {

        int now = root;

        for (int i = 0; buf[i]; i++)

        {

            int id = get_id(buf[i]);

            if (next[now][id] == -1)

                next[now][id] = newnode();

            now = next[now][id];

        }

        virus[now] = true;

        D(printf("virus[%d] = %d\n", now, virus[now]));

    }



    void build()

    {

        queue<int>Q;

        fail[root] = root;

        for (int i = 0; i < MAX_CHILD_NUM; 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 < MAX_CHILD_NUM; i++)

                if (next[now][i] == -1)

                    next[now][i] = next[fail[now]][i];

                else

                {

                    fail[next[now][i]]=next[fail[now]][i];

                    if (virus[fail[next[now][i]]])

                        virus[next[now][i]] = true;

                    Q.push(next[now][i]);

                }

        }

    }



    bool dfs(int u)

    {

        D(printf("%d\n", u));

        vis[u] = true;

        for (int i = 0; i < MAX_CHILD_NUM; i++)

        {

            int v = next[u][i];

            D(printf(" %d\n", v));

            if (virus[v])

                continue;

            if (vis[v])

                return true;

            if (dfs(v))

                return true;

        }

        vis[u] = false;

        return false;

    }



    void debug()

    {

        for(int i = 0;i < node_cnt;i++)

        {

            printf("id = %3d,fail = %3d,end = %3d,chi = [",i,fail[i],virus[i]);

            for(int j = 0;j < MAX_CHILD_NUM;j++)

                printf("%2d",next[i][j]);

            printf("]\n");

        }

    }

}ac;



char st[MAX_LEN];

int n;



int main()

{

    scanf("%d", &n);

    ac.init();

    for (int i = 0; i < n; i++)

    {

        scanf("%s", st);

        ac.insert(st);

    }

    ac.build();

    memset(ac.vis, 0, sizeof(ac.vis));

    if (ac.dfs(ac.root))

        puts("TAK");

    else

        puts("NIE");

    return 0;

}

View Code