hihocoder 后缀自动机二·重复旋律5

求不同子串个数

裸的后缀自动机

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

#define ll long long
#define N 2000007
using namespace std;
inline int read()
{
    int x=0,f=1;char ch=getchar();
    while(!isdigit(ch)){if(ch=='-')f=-1;ch=getchar();}
    while(isdigit(ch)){x=(x<<1)+(x<<3)+ch-'0';ch=getchar();}
    return x*f;
}

int n;
ll ans;
struct sam
{
    int last,cnt;
    int c[N][26],fa[N],mx[N];
    sam(){last=cnt=1;}
    void extend(int x)
    {
        int p=last,np=last=++cnt;mx[np]=mx[p]+1;
        while(p&&!c[p][x])
        {
            c[p][x]=np;
            p=fa[p];
        }
        if(!p)fa[np]=1;
        else
        {
            int q=c[p][x];
            if(mx[q]==mx[p]+1)fa[np]=q;
            else
            {
                int nq=++cnt;mx[nq]=mx[p]+1;
                memcpy(c[nq],c[q],sizeof(c[q]));
                fa[nq]=fa[q];
                fa[q]=fa[np]=nq;
                while(c[p][x]==q)c[p][x]=nq,p=fa[p];
            }
        }
    }
}sam;
char s[N];

int main()
{
    scanf("%s",s+1);n=strlen(s+1);
    for (int i=1;i<=n;i++)
        sam.extend(s[i]-'a');
    for (int i=1;i<=sam.cnt;i++)
        ans+=sam.mx[i]-sam.mx[sam.fa[i]];
    printf("%lld",ans);
}