zoj 3430 Detect the Virus(AC自动机)

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题目连接：zoj 3430 Detect the Virus

题目大意：给定一个编码完的串，将每一个字符对应着表的数值转换成6位二进制，然后以8为一个数值，重新形成字符

串，判断给定询问串是否含有字符集中的串。

解题思路：主要是题意，逆编码部分注意，转换完了之后，可能有字符'\0'，所以不能用字符串的形式储存，要用int型

的数组。注意有相同串的可能。

#include <cstdio>#include <cstring>#include <queue>#include <vector>#include <iostream>#include <algorithm>using namespace std;typedef long long ll;const int maxn = 512 * 100;const int sigma_size = 256;struct Aho_Corasick {    int sz, g[maxn][sigma_size];    int tag[maxn], fail[maxn], last[maxn];    bool vis[520];    int jump[520];    void init();    int idx(char ch);    void insert(int* str, int k);    void getFail();    int match(int* str);    void put(int u);}A;inline int change(char ch) {    if (ch >= 'A' && ch <= 'Z')        return ch - 'A';    if (ch >= 'a' && ch <= 'z')        return ch - 'a' + 26;    if (ch >= '0' && ch <= '9')        return ch - '0' + 52;    if (ch == '+')        return 62;    return 63;}const int maxl = 5005;char w[maxl];int s[maxl * 2];void input(int* s) {    scanf("%s", w);    s[0]=0;      int n = strlen(w);    while (n && w[n-1] == '=') n--;    w[n] = 0;    for(int i=0,len=0,x=0;w[i];++i){          len+=6,x=(x<<6)|change(w[i]);          if(len>=8){              s[++s[0]]=(x>>(len-8))&0xff;            len-=8;           }      }     /*       for(int i = 1; i <= s[0]; i++)       printf(" %d", s[i]);       printf("\n");       */}int N, M;int main () {    while (scanf("%d", &N) == 1) {        A.init();        for (int i = 1; i <= N; i++) {            input(s);            A.insert(s, i);        }        A.getFail();        scanf("%d", &M);        for (int i = 1; i <= M; i++) {            input(s);            printf("%d\n", A.match(s));        }        printf("\n");    }    return 0;}void Aho_Corasick::init() {    sz = 1;    tag[0] = 0;    memset(g[0], 0, sizeof(g[0]));}int Aho_Corasick::idx(char ch) {    return ch;}void Aho_Corasick::put(int u) {    int p = tag[u];    while (p && vis[p] == 0) {        vis[p] = 1;        p = jump[p];    }    if (last[u])        put(last[u]);}void Aho_Corasick::insert(int* str, int k) {    int u = 0;    for (int i = 1; i <= str[0]; i++) {        int v = str[i];        while (v >= sigma_size);        if (g[u][v] == 0) {            tag[sz] = 0;            memset(g[sz], 0, sizeof(g[sz]));            g[u][v] = sz++;        }        u = g[u][v];    }    jump[k] = tag[u];    tag[u] = k;}int Aho_Corasick::match(int* str) {    memset(vis, 0, sizeof(vis));    int u = 0;    for (int i = 1; i <= str[0]; i++) {        int v = str[i];        while (v >= sigma_size);        while (u && g[u][v] == 0)            u = fail[u];        u = g[u][v];        if (tag[u])            put(u);        else if (last[u])            put(last[u]);    }    int ret = 0;    for (int i = 1; i <= N; i++)        if (vis[i])            ret++;    return ret;}void Aho_Corasick::getFail() {    queue<int> que;    for (int i  = 0; i < sigma_size; i++) {        int u = g[0][i];        if (u) {            fail[u] = last[u] = 0;            que.push(u);        }    }    while (!que.empty()) {        int r = que.front();        que.pop();        for (int i = 0; i < sigma_size; i++) {            int u = g[r][i];            if (u == 0) {                g[r][i] = g[fail[r]][i];                continue;            }            que.push(u);            int v = fail[r];            while (v && g[v][i] == 0)                v = fail[v];            fail[u] = g[v][i];            last[u] = tag[fail[u]] ? fail[u] : last[fail[u]];        }    }}

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