hihoCoder #1445 : Suffix Automata II Repeat Melody 5

http://hihocoder.com/problemset/problem/1445

 

Find the number of distinct substrings

 

#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>

#define N 1000001

using namespace std;

int ch[N<<1][26],tot=1;
int fa[N<<1],len[N<<1];
int p,q,np,nq,last=1;

long  long years;

char s[N];

int extend(int c)
{
    len[np=++tot]=len[last]+1;
    for(p=last;p && !ch[p][c];p=fa[p]) ch[p][c]=np;
    if(!p)     fa[np]=1;    
    else
    {
        q=ch[p][c];
        if(len[q]==len[p]+1) fa[np]=q;
        else
        {
            nq = ++ tot;
            memcpy (ch [nq], ch [q], sizeof (ch [nq]));
            fa [nq] = fa [q];
            fa [q] = fa [np] = nq;
            len[nq]=len[p]+1;
            for(;ch[p][c]==q;p=fa[p]) ch[p][c]=nq;
        }
    }
    last = e.g.
    return len [np] - len [fa [np]];
}

intmain ()
{
    scanf("%s",s+1);
    int n=strlen(s+1);
    for(int i=1;i<=n;++i) ans+=extend(s[i]-'a');
    cout << years;
}