0、题意:给定N个原始字符串S,M次查询某个特殊的字符串S’在多少个原始串中出现过。
1、分析:这个题我们第一感觉就是可以用后缀自动机来搞,然后我们发现不是本质不同的字串。。求出现过的次数,也就是说多次出现只算一次。。。然后我们依旧用建立后缀自动机,然后我们观察到询问是可以离线的。。然后冷静一下QAQ……好了。。询问可以离线后,我们对这个树形结构求一下dfs序,然后我们就可以把树上的询问变成一个序列的区间查询,然后就变成了BZOJ1878HH的项链。。具体怎么搞呢?我们可以将询问排序,然后离线的扫一遍,记录一下x的颜色的上一次出现位置,然后转移就好
#include <map>
#include <set>
#include <cmath>
#include <queue>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <algorithm>
using namespace std;
inline int read(){
char ch = getchar(); int x = 0, f = 1;
while(ch < '0' || ch > '9'){
if(ch == '-') f = -1;
ch = getchar();
}
while('0' <= ch && ch <= '9'){
x = x * 10 + ch - '0';
ch = getchar();
}
return x * f;
}
struct Edge{
int u, v, next;
} G[400010];
int head[200010], tot;
char str[500010];
int first[200010], val[200010], nxt[200010], num;
int C[200010];
int n, m;
int pre[200010];
inline void ues(int u, int v){
num ++;
val[num] = v;
nxt[num] = first[u];
first[u] = num;
}
inline void add(int x, int y){
G[++ tot] = (Edge){x, y, head[x]};
head[x] = tot;
}
map<int , int> :: iterator it;
int vis[200010];
int last, cnt, p, np, q, nq;
int len[200010], fa[200010];
map<int , int> tranc[200010];
int right[200010], c[200010], od[200010];
int tim;
int ans[200010];
inline void insert(int c, int w){
p = last;
if(tranc[p][c] != 0){
q = tranc[p][c];
if(len[q] == len[p] + 1) last = tranc[p][c];
else{
nq = ++ cnt; len[nq] = len[p] + 1;
for(it = tranc[q].begin(); it != tranc[q].end(); it ++){
tranc[nq][it -> first] = it -> second;
}
fa[nq] = fa[q];
fa[q] = nq;
while(tranc[p][c] == q){
tranc[p][c] = nq;
p = fa[p];
}
last = nq;
}
}
else{
last = np = ++ cnt;
vis[np] = 1;
len[np] = len[p] + 1;
tranc[cnt].clear();
right[np] = 1;
while(!tranc[p][c] && p) tranc[p][c] = np, p = fa[p];
if(!p) fa[np] = 1;
else{
q = tranc[p][c];
if(len[q] == len[p] + 1) fa[np] = q;
else{
nq = ++ cnt; len[nq] = len[p] + 1;
for(it = tranc[q].begin(); it != tranc[q].end(); it ++){
tranc[nq][it -> first] = it -> second;
}
fa[nq] = fa[q];
fa[q] = fa[np] = nq;
while(tranc[p][c] == q){
tranc[p][c] = nq;
p = fa[p];
}
}
}
last = np;
}
ues(last, w);
}
inline void init(){
memset(head, -1, sizeof(head));
for(int i = 1; i <= cnt; i ++){
add(fa[i], i);
}
}
inline void update(int x, int d){
if(x == 0) return;
for(; x <= cnt; x += (x & -x)){
C[x] += d;
}
}
inline int sum(int x){
int ret = 0;
for(; x > 0; x -= (x & -x)){
ret += C[x];
}
return ret;
}
inline void dfs(int x){
int t = ++ tim;
for(int i = first[x]; i; i = nxt[i]){
update(pre[val[i]], -1);
update(t, 1);
pre[val[i]] = t;
}
for(int i = head[x]; i != -1; i = G[i].next){
dfs(G[i].v);
}
ans[x] = sum(tim) - sum(t - 1);
}
int query(char *s)
{
int st = 1;
while(*s != '\0')
st = tranc[st][*s], s ++;
return st;
}
int main(){
last = cnt = 1;
n = read(); m = read();
for(int i = 1; i <= n; i ++){
last = 1;
scanf("%s", str + 1);
int L = strlen(str + 1);
for(int j = 1; j <= L; j ++){
insert(str[j], i);
}
}
init();
dfs(1);
for(int i = 1; i <= m; i ++){
scanf("%s", str);
printf("%d\n", ans[query(str)]);
}
return 0;
}