BZOJ 4516: [Sdoi2016]生成魔咒 [后缀自动机]

4516: [Sdoi2016]生成魔咒

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <cmath>
#include <map>
using namespace std;
typedef long long ll;
#define fir first
#define sec second
const int N=3e5+5, P=1e9+7;
inline int read() {
char c=getchar(); int x=0, f=1;
while(c<'0' || c>'9') {if(c=='-')f=-1; c=getchar();}
while(c>='0' && c<='9') {x=x*10+c-'0'; c=getchar();}
return x*f;
}

int n, s
; ll ans;
struct meow { map<int, int> ch; int par, val;}t
;
int sz=1, root=1, last=1;
void extend(int c) {
int p=last, np=++sz;
t[np].val = t[p].val+1;
for(; p && !t[p].ch[c]; p=t[p].par) t[p].ch[c]=np;
if(!p) t[np].par = root;
else {
int q=t[p].ch[c];
if(t[q].val == t[p].val+1) t[np].par=q;
else {
ans -= t[q].val - t[p].val;
int nq=++sz; t[nq]=t[q]; t[nq].val = t[p].val+1;
t[q].par = t[np].par = nq;
ans += t[q].val - t[nq].val; ans ++;
for(; p && t[p].ch[c]==q; p=t[p].par) t[p].ch[c] = nq;
}
}
ans+=t[np].val - t[t[np].par].val;
last=np;
}
int main() {
//freopen("in","r",stdin);
freopen("incantation.in","r",stdin);
freopen("incantation.out","w",stdout);
n=read();
for(int i=1; i<=n; i++) {
s[i]=read();
extend(s[i]);
printf("%lld\n",ans);
}
}