BZOJ 2555 SubString 后缀自动机

题目大意：

如题面所述, 在线状态下接受添加字符和查询某个字符串出现的次数

加上了一些加密的条件使得被迫在线查询

大致思路：

就是后缀自动机的裸题吧=_=

没什么特别的, 直接贴代码好了, 不懂的看代码细节吧

代码如下：

Result  :  Accepted     Memory  :  140140 KB     Time  :  6044 ms

/*
* Author: Gatevin
* Created Time: 2015/5/5 17:57:21
* File Name: Rin_Tohsaka.cpp
*/
#include<iostream>
#include<sstream>
#include<fstream>
#include<vector>
#include<list>
#include<deque>
#include<queue>
#include<stack>
#include<map>
#include<set>
#include<bitset>
#include<algorithm>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cctype>
#include<cmath>
#include<ctime>
#include<iomanip>
using namespace std;
const double eps(1e-8);
typedef long long lint;
#define foreach(e, x) for(__typeof(x.begin()) e = x.begin(); e != x.end(); ++e)
#define SHOW_MEMORY(x) cout<<sizeof(x)/(1024*1024.)<<"MB"<<endl

#define maxm 600010
#define maxn 1200010
#define maxl 3000010

struct Suffix_Automation
{
struct State
{
State *par;
State *go[26];
int right, val;
void init(int _val = 0)
{
val = _val, par = 0, right = 0;
memset(go, 0, sizeof(go));
}
};
State *root, *last, *cur;
State nodePool[maxn];
State* newState(int val = 0)
{
cur->init(val);
return cur++;
}
void init()
{
cur = nodePool;
root = newState();
last = root;
}
void extend(int w)
{
State *p = last;
State *np = newState(p->val + 1);
np->right = 1;
while(p && p->go[w] == 0)
{
p->go[w] = np;
p = p->par;
}
if(p == 0)
{
np->par = root;
}
else
{
State *q = p->go[w];
if(p->val + 1 == q->val)
{
np->par = q;
}
else
{
State *nq = newState(p->val + 1);
memcpy(nq->go, q->go, sizeof(q->go));
nq->right = q->right;
nq->par = q->par;
q->par = nq;
np->par = nq;
while(p && p->go[w] == q)
{
p->go[w] = nq;
p = p->par;
}
}
}
last = np;
}
void update()
{
State *tmp = last;
while(tmp != root)
{
tmp->par->right++;
tmp = tmp->par;
}
}
int ask(char *s, int len)//询问这个串出现了几次
{
State *now = root;
for(int i = 0; i < len; i++)
{
int w = s[i] - 'A';
if(now->go[w])
now = now->go[w];
else
{
printf("0\n");
return 0;
}
}
printf("%d\n", now->right);
return now->right;
}
};

char s[maxl];

Suffix_Automation sam;

void decode(char *s, int len, int mask)
{
for(int j = 0; j < len; j++)
{
mask = (mask*131 + j) % len;
swap(s[j], s[mask]);
}
return;
}

int main()
{
int Q;
int mask = 0;
scanf("%d", &Q);
scanf("%s", s);
int len = strlen(s);
sam.init();
for(int i = 0; i < len; i++)
sam.extend(s[i] - 'A'), sam.update();
while(Q--)
{
scanf("%s", s);
switch(s[0])
{
case 'Q': scanf("%s", s);
len = strlen(s);
decode(s, len, mask);
mask ^= sam.ask(s, len);
break;
case 'A': scanf("%s", s);
len = strlen(s);
decode(s, len, mask);
for(int i = 0; i < len; i++)
sam.extend(s[i] - 'A'), sam.update();
break;
}
}
return 0;
}