求不同的子串种类

#include<iostream>
#include<algorithm>
#include<cstring>
#include<cstdio>
using namespace std;
typedef long long ll;
const int maxn=1000006;
int trans[maxn<<1][26],slink[maxn<<1],maxlen[maxn<<1];
int endpos[maxn<<1];
int last,now,root,len;
void init(){
    now=last=root=1;
    memset(trans,0,sizeof(trans));
    memset(maxlen,0,sizeof(maxlen));
    memset(slink,0,sizeof(slink));
}
void extend(int c){
    maxlen[++now]=maxlen[last]+1;
    int p=last,np=now;
    while(p&&!trans[p][c]){
        trans[p][c]=np;
        p=slink[p];
    }
    if(!p)
        slink[np]=root;
    else{
        int q=trans[p][c];
        if(maxlen[p]+1!=maxlen[q]){
            maxlen[++now]=maxlen[p]+1;
            int nq=now;
            memcpy(trans[nq],trans[q],sizeof(trans[q]));
            slink[nq]=slink[q];
            slink[q]=slink[np]=nq;
            while(p&&trans[p][c]==q){
                trans[p][c]=nq;
                p=slink[p];
            }
        }
        else
            slink[np]=q;
    }
    last=np;
    endpos[np]=1;
}
ll all(){
    ll ans=0;
    for(int i=root+1;i<=now;i++){
        ans+=maxlen[i]-maxlen[slink[i]];///minlen=maxlen[slink[i]]
    
    }
    return ans;
}
int main(){
    string s;
    init();
    cin>>s;
    len=s.size();
    for(int i=0;i<len;i++)
        extend(s[i]-‘a‘);
    cout<<all()<<endl;
    return 0;
}