用SAM建广义后缀树

原文

写的还比较详细,所以本蒟蒻就不再自己写一个了……
用SAM建广义后缀树

例题

TJOI的单词
离线构造

#include<cstdio>
#include<algorithm>
#include<cstring>
#define fo(i,a,b) for(i=a;i<=b;i++)
#define fd(i,a,b) for(i=a;i>=b;i--)
using namespace std;
const int maxn=2500000+10;
int pre[maxn],step[maxn],size[maxn],g[maxn][27],id[maxn];
char s[maxn],ch;
int i,j,k,l,t,n,m,tot,top,last;
struct dong{
    int len,id;
} a[250];
bool operator <(dong a,dong b){
    return a.len<b.len;
}
char get(){
    char ch=getchar();
    while (ch<'a'||ch>'z') ch=getchar();
    return ch;
}
void insert(char ch){
    if (g[last][ch-'a']&&step[g[last][ch-'a']]==step[last]+1){
        last=g[last][ch-'a'];
        size[last]++;
        return;
    }
    int np=++tot;
    size[np]=1;
    step[np]=step[last]+1;
    int p=last;
    while (p&&g[p][ch-'a']==0){
        g[p][ch-'a']=np;
        p=pre[p];
    }
    if (!p) pre[np]=1;
    else{
        int q=g[p][ch-'a'];
        if (step[q]==step[p]+1) pre[np]=q;
        else{
            int nq=++tot;
            step[nq]=step[p]+1;
            pre[nq]=pre[q];
            pre[q]=nq;
            int i;
            fo(i,0,26) g[nq][i]=g[q][i];
            pre[np]=nq;
            while (p&&g[p][ch-'a']==q){
                g[p][ch-'a']=nq;
                p=pre[p];
            }
        }
    }
    last=np;
}
bool cmp(int a,int b){
    if (step[a]<step[b]) return 1;
    else if (step[a]==step[b]&&a>b) return 1;
    else return 0;
}
int main(){
    //freopen("word4.in","r",stdin);freopen("3127.out","w",stdout);
    scanf("%d",&n);
    tot=1;
    fo(i,1,n){
        s[++top]=get();
        while (1){
            ch=getchar();
            if (ch<'a'||ch>'z') break;
            s[++top]=ch;
        }
        s[++top]='a'+26;
        a[i].len=top-a[i-1].id-a[i-1].len-1;
        a[i].id=top-a[i].len;
    }
    sort(a+1,a+n+1);
    fo(i,1,n){
        last=1;
        fo(j,a[i].id,a[i].id+a[i].len-1) insert(s[j]);
    }
    fo(i,1,tot) id[i]=i;
    sort(id+1,id+tot+1,cmp);
    fd(i,tot,1)
        if (pre[id[i]]>1) size[pre[id[i]]]+=size[id[i]];
    j=1;
    fo(i,1,top){
        if (s[i]=='a'+26){
            printf("%d\n",size[j]);
            j=1;
        }
        else j=g[j][s[i]-'a'];
    }
}

在线构造

#include<cstdio>
#include<algorithm>
#include<cstring>
#define fo(i,a,b) for(i=a;i<=b;i++)
#define fd(i,a,b) for(i=a;i>=b;i--)
using namespace std;
const int maxn=2500000+10;
int pre[maxn],step[maxn],size[maxn],g[maxn][27],id[maxn];
char s[maxn],ch;
int i,j,k,l,t,n,m,tot,top,last;
char get(){
    char ch=getchar();
    while (ch<'a'||ch>'z') ch=getchar();
    return ch;
}
void insert(char ch){
    if (g[last][ch-'a']){
        int p=last,q=g[p][ch-'a'];
        if (step[q]==step[p]+1){
            last=g[last][ch-'a'];
            size[last]++;
        }
        else{
            int nq=++tot;
            step[nq]=step[p]+1;
            pre[nq]=pre[q];
            pre[q]=nq;
            int i;
            fo(i,0,26) g[nq][i]=g[q][i];
            while (p&&g[p][ch-'a']==q){
                g[p][ch-'a']=nq;
                p=pre[p];
            }
            last=nq;
            size[last]++;
            return;
        }
        return;
    }
    int np=++tot;
    size[np]=1;
    step[np]=step[last]+1;
    int p=last;
    while (p&&g[p][ch-'a']==0){
        g[p][ch-'a']=np;
        p=pre[p];
    }
    if (!p) pre[np]=1;
    else{
        int q=g[p][ch-'a'];
        if (step[q]==step[p]+1) pre[np]=q;
        else{
            int nq=++tot;
            step[nq]=step[p]+1;
            pre[nq]=pre[q];
            pre[q]=nq;
            int i;
            fo(i,0,26) g[nq][i]=g[q][i];
            pre[np]=nq;
            while (p&&g[p][ch-'a']==q){
                g[p][ch-'a']=nq;
                p=pre[p];
            }
        }
    }
    last=np;
}
bool cmp(int a,int b){
    if (step[a]<step[b]) return 1;
    else if (step[a]==step[b]&&a<b) return 1;
    else return 0;
}
int main(){
    //freopen("word4.in","r",stdin);freopen("3127.out","w",stdout);
    scanf("%d",&n);
    last=tot=1;
    fo(i,1,n){
        s[++top]=get();
        insert(s[top]);
        while (1){
            ch=getchar();
            if (ch<'a'||ch>'z') break;
            s[++top]=ch;
            insert(s[top]);
        }
        s[++top]='a'+26;
        last=1;
    }
    fo(i,1,tot) id[i]=i;
    sort(id+1,id+tot+1,cmp);
    fd(i,tot,1)
        if (pre[id[i]]>1) size[pre[id[i]]]+=size[id[i]];
    j=1;
    fo(i,1,top){
        if (s[i]=='a'+26){
            printf("%d\n",size[j]);
            j=1;
        }
        else j=g[j][s[i]-'a'];
    }
}

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