hdu 3065 病毒侵袭持续中

http://acm.hdu.edu.cn/showproblem.php?pid=3065

　　继续简单AC自动机，1y~

#include <cstdio>
#include <cstring>
#include <algorithm>
#include <set>
#include <cstdlib>

using namespace std;

const int kind = 256;
const int maxn = 51 * 1001;

struct Node{
    int fail;
    int next[kind];
    int count;
    void init(){
        fail = -1;
        count = 0;
        memset(next, -1, sizeof(next));
    }
}node[maxn];

char keyword[51];
char str[2000005];
int head, tail, nodeUsed;
int q[maxn];

void insert(char *s, int root, int num){
    int p = root;
    int i = 0, index;

    while (s[i]){
        index = s[i];
        if (node[p].next[index] == -1){
            node[p].next[index] = nodeUsed;
            node[nodeUsed].init();
            nodeUsed++;
        }
        p = node[p].next[index];
        i++;
    }
    node[p].count = num;
}

void build(int root){
    int i;

    node[root].fail = -1;
    head = tail = 0;
    q[head++] = root;
    while (head != tail){
        int temp = q[tail++];
        int p = -1;

        for (i = 0; i < kind; i++){
            if (node[temp].next[i] != -1){
                if (temp == root) node[node[temp].next[i]].fail = root;
                else{
                    p = node[temp].fail;
                    while (p != -1){
                        if (node[p].next[i] != -1){
                            node[node[temp].next[i]].fail = node[p].next[i];
                            break;
                        }
                        p = node[p].fail;
                    }
                    if (p == -1) node[node[temp].next[i]].fail = root;
                }
                q[head++] = node[temp].next[i];
            }
        }
    }
}

char buf[1001][51];
int cnt[1001];

void query(int root){
    int i = 0, index;
    int p = root;

    memset(cnt, 0, sizeof(cnt));
    while (str[i]){
        index = str[i];
        while (node[p].next[index] == -1 && p != root) p = node[p].fail;
        p = node[p].next[index];
        p = (p == -1) ? root : p;

        if (node[p].count) cnt[node[p].count]++;
        i++;
    }
}

void traverse(int root){
    if (root == -1) return ;
    printf("root %d\n", root);
    printf("fail %d\n", node[root].fail);
    printf("count %d\n", node[root].count);
    for (int i = 0; i < kind; i++){
        if (node[root].next[i] == -1) continue;
        printf("%c %d\n", i + 'a', node[root].next[i]);
    }
    puts("");
    for (int i = 0; i < kind; i++){
        traverse(node[root].next[i]);
    }
}

int main(){
    int n;

//freopen("in", "r", stdin);
    while (~scanf("%d", &n)){
        int root = 0;

        node[0].init();
        nodeUsed = 1;

        for(int i = 1; i <= n; i++){
            scanf("%s", keyword);
            strcpy(buf[i], keyword);
            insert(keyword, root, i);
        }
        build(root);
//traverse(root);
//puts("Built!");

        scanf("%s", str);
        query(root);
        for (int i = 1; i <= n; i++){
            if (cnt[i]) printf("%s: %d\n", buf[i], cnt[i]);
        }
    }

    return 0;
}

——written by Lyon