回文自动机

今天上午LargeDumpling给我来了一发字符串专题Orz
于是下午来了一发回文自动机
板：
 1 #include<algorithm>
 2 #include<iostream>
 3 #include<cstdlib>
 4 #include<cstring>
 5 #include<cstdio>
 6 #include<string>
 7 #include<cmath>
 8 #include<ctime>
 9 #include<queue>
10 #include<stack>
11 #include<map>
12 #include<set>
13 #define rre(i,r,l) for(int i=(r);i>=(l);i--)
14 #define re(i,l,r) for(int i=(l);i<=(r);i++)
15 #define Clear(a,b) memset(a,b,sizeof(a))
16 #define inout(x) printf("%d",(x))
17 #define douin(x) scanf("%lf",&x)
18 #define strin(x) scanf("%s",(x))
19 #define LLin(x) scanf("%lld",&x)
20 #define op operator
21 #define CSC main
22 typedef unsigned long long ULL;
23 typedef const int cint;
24 typedef long long LL;
25 using namespace std;
26 void inin(int &ret)
27 {
28     ret=0;int f=0;char ch=getchar();
29     while(ch<'0'||ch>'9'){if(ch=='-')f=1;ch=getchar();}
30     while(ch>='0'&&ch<='9')ret*=10,ret+=ch-'0',ch=getchar();
31     ret=f?-ret:ret;
32 }
33 const int xxxx=600010;//length
34 namespace pam
35 {
36     int ch[xxxx][26];//son
37     int pre[xxxx];//fail
38     int sum[xxxx];//times
39     int len[xxxx];//Max_length
40     int ss[xxxx];//string
41     int num[xxxx];//numbers
42     int last,n,ed=-1;
43     int newnode(int x)//you_know
44     {
45         len[++ed]=x;
46         return ed;
47     }
48     void init()//pretreatment
49     {
50         newnode(0),newnode(-1);
51         last=n=0;ss[n]=-1,pre[0]=pre[1]=1;
52     }
53     int getfail(int x)//you_know
54     {
55         while(ss[n-len[x]-1]!=ss[n])x=pre[x];
56         return x;
57     }
58     void add(int c)//add_a_char
59     {
60         c-='a';
61         ss[++n]=c;
62         int temp=getfail(last);
63         if(!ch[temp][c])
64         {
65             int now=newnode(len[temp]+2);
66             int k=getfail(pre[temp]);
67             pre[now]=ch[k][c];
68             ch[temp][c]=now;
69             num[now]=num[pre[now]]+1;
70         }
71         last=ch[temp][c];
72         sum[last]++;
73     }
74     void add(char *s)//add_a_string
75     {
76         int limit=strlen(s);
77         re(i,0,limit-1)add(s[i]);
78     }
79     void count()//clac_times
80     {
81         rre(i,ed,1)sum[pre[i]]+=sum[i];
82     }
83 }
84 char s[xxxx];
85 int main()
86 {
87     strin(s);
88     pam::init();
89     pam::add(s);
90     pam::count();
91     return 0;
92 }