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
", 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
", u));
        vis[u] = true;
        for (int i = 0; i < MAX_CHILD_NUM; i++)
        {
            int v = next[u][i];
            D(printf(" %d
", 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("]
");
        }
    }
}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;
}