HDU 3065 病毒侵袭持续中——AC自动机

注意文本串为可见字符，套用模板时不能单纯的减去'A',一种解决方法是把SIZE开到128，不过这样非常不负责任。。。另一种解决方法是在查找时找到大写字母以外的字符就把root设为0，并且continue；注意不能预处理出大写字母，否则AxxxxxA会预处理出AA，如果模式串为AA就出错了（当然预处理也有一种解决方法，不过挺麻烦，不推荐）

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
#include <queue>
using namespace std;
const int MAXL = 2 * 1e6 + 10;
const int MAXN = 1e5;
const int SIZE = 26;

char str1[1010][55], str2[MAXL];
int n, ans[1010];
struct AC {
int total, val[MAXN], fail[MAXN], child[MAXN][SIZE];
void init() {
total = 1;
memset(val, 0, sizeof(val));
memset(fail, 0, sizeof(fail));
memset(child[0], 0, sizeof(child[0]));
}
void Insert(char *P, int id) {
int len = strlen(P), root = 0;
for (int i = 0; i < len; i++) {
if (!child[root][P[i] - 'A']) {
memset(child[total], 0, sizeof(child[total]));
child[root][P[i] - 'A'] = total++;
}
root = child[root][P[i] - 'A'];
}
val[root] = id;
}
void Getfail() {
queue<int> q;
for (int i = 0; i < SIZE; i++) {
if (child[0][i]) q.push(child[0][i]);
}
while (!q.empty()) {
int root = q.front(); q.pop();
for (int i = 0; i < SIZE; i++) {
int u = child[root][i];
if (!u) { child[root][i] = child[fail[root]][i]; continue; }
q.push(u);
int v = fail[root];
while (v && !child[v][i]) v = fail[v];
fail[u] = child[v][i];
}
}
}
void Search(char *T) {
Getfail();
int len = strlen(T), root = 0, temp;
for (int i = 0; i < len; i++) {
if ('Z' < T[i] || T[i] < 'A') { root = 0; continue; }
temp = root = child[root][T[i] - 'A'];
while (temp && val[temp]) {
ans[val[temp]]++;
temp = fail[temp];
}
}
}
}ac;

int main()
{
while (~scanf("%d", &n)) {
memset(ans, 0, sizeof(ans));
ac.init();
for (int i = 1; i <= n; i++) {
scanf("%s", str1[i]); ac.Insert(str1[i], i);
}
getchar(); gets(str2);
ac.Search(str2);
for (int i = 1; i <= n; i++) {
if (ans[i]) {
printf("%s: %d\n", str1[i], ans[i]);
}
}
}
return 0;
}