【bzoj4212】神牛的养成计划 Trie树+可持久化Trie树

#include <cstdio>
#include <cstring>
#include <algorithm>
#define N 2000010
using namespace std;
int next[26][N] , fa[N] , tag[N] , lp[N] , rp[N] , tot = 1 , cnt , root[N] , c[26][N] , si[N] , num , len;
char str[N] , ch[N] , ss[N] , ll;
void insert(int x , int &y)
{
	int i , j , t = ++num;
	y = t;
	for(i = 0 ; i < len ; i ++ )
	{
		for(j = 0 ; j < 26 ; j ++ ) c[j][t] = c[j][x];
		c[str[i] - ‘a‘][t] = ++num , x = c[str[i] - ‘a‘][x] , t = c[str[i] - ‘a‘][t] , si[t] = si[x] + 1;
	}
	for(i = 0 ; i < 26 ; i ++ ) c[i][t] = c[i][x];
}
int query(int x , int y)
{
	int i;
	for(i = len - 1 ; ~i ; i -- ) x = c[str[i] - ‘a‘][x] , y = c[str[i] - ‘a‘][y];
	return si[y] - si[x];
}
void dfs(int x)
{
	int i;
	if(tag[x])
	{
		len = 0 , lp[x] = rp[x] = ++cnt;
		for(i = x ; i != 1 ; i = fa[i]) str[len ++ ] = ch[i];
		insert(root[cnt - 1] , root[cnt]);
		return;
	}
	lp[x] = 1 << 30 , rp[x] = -1 << 30;
	for(i = 0 ; i < 26 ; i ++ )
		if(next[i][x])
			dfs(next[i][x]) , lp[x] = min(lp[x] , lp[next[i][x]]) , rp[x] = max(rp[x] , rp[next[i][x]]);
}
void trans(char *s , int ans)
{
	int i , l = strlen(s);
	for(i = 0 ; i < l ; i ++ ) s[i] = (s[i] - ‘a‘ + ans) % 26 + ‘a‘;
}
int main()
{
	int n , m , i , j , l , t , ans = 0;
	scanf("%d" , &n);
	for(i = 1 ; i <= n ; i ++ )
	{
		scanf("%s" , str) , l = strlen(str);
		for(j = 0 , t = 1 ; j < l ; j ++ )
		{
			if(!next[str[j] - ‘a‘][t]) next[str[j] - ‘a‘][t] = ++tot , ch[tot] = str[j] , fa[tot] = t;
			t = next[str[j] - ‘a‘][t];
		}
		tag[t] = 1;
	}
	dfs(1);
	scanf("%d" , &m);
	for(i = 1 ; i <= m ; i ++ )
	{
		scanf("%s%s" , ss , str) , trans(ss , ans) , trans(str , ans) , l = strlen(ss) , len = strlen(str);
		for(j = 0 , t = 1 ; t && j < l ; j ++ ) t = next[ss[j] - ‘a‘][t];
		if(t) printf("%d\n" , ans = query(root[lp[t] - 1] , root[rp[t]]));
		else printf("%d\n" , ans = 0);
	}
	return 0;
}