bzoj 4566: [Haoi2016]找相同字符

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#define N 800005
using namespace std;
int read()
{
int p=0;char c=getchar();
while(c<'0'||c>'9')c=getchar();
while(c>='0'&&c<='9')p=p*10+c-'0',c=getchar();
return p;
}
int n,m;
char s
,ss[200004],sss[200004];
int l
,tot,fa
,ch
[30],v1
,v2
;
long long ans;
int qq
;
bool cmp(int x,int y)
{
return l[x]>l[y];
}
void build()
{
int lst=0;
for(int i=0;i<=n+m;i++)
{
int c=s[i]-'a';
int p=lst;int np=++tot;lst=np;
l[np]=l[p]+1;
if(i<n)v1[np]=1;
if(i>n)v2[np]=1;
while(p&&!ch[p][c])ch[p][c]=np,p=fa[p];
int q=ch[p][c];
if(!q)
{
ch[p][c]=np;
continue;
}
else if(l[q]==l[p]+1)
{
fa[np]=q;
continue;
}
tot++;fa[tot]=fa[q];
fa[q]=fa[np]=tot;
l[tot]=l[p]+1;
for(int j=0;j<27;j++)ch[tot][j]=ch[q][j];
while(p&&ch[p][c]==q)ch[p][c]=tot,p=fa[p];
if(ch[p][c]==q)ch[p][c]=tot;
}
for(int i=0;i<=tot;i++)qq[i]=i;
sort(qq,qq+tot+1,cmp);
for(int i=0;i<=tot;i++)
{
v1[fa[qq[i]]]+=v1[qq[i]];
v2[fa[qq[i]]]+=v2[qq[i]];
}
for(int i=0;i<=tot;i++)
{
ans+=(long long)(l[i]-l[fa[i]])*v1[i]*v2[i];
}
return ;
}
int main()
{
scanf("%s",ss);
scanf("%s",sss);
n=strlen(ss);m=strlen(sss);
for(int i=0;i<n;i++)s[i]=ss[i];
s
='z'+1;
for(int i=0;i<m;i++)s[i+n+1]=sss[i];
build();
printf("%lld\n",ans);
return 0;
}
/*
babb
abbb
*/