定义为以开头结尾的最短的不会被别的串表示出来的串
这个可以在上得到
考虑二分答案
于是只需要看次拼出的串是否比大即可
#include<bits/stdc++.h>
using namespace std;
const int RLEN=1<<20|1;
inline char gc(){
static char ibuf[RLEN],*ib,*ob;
(ob==ib)&&(ob=(ib=ibuf)+fread(ibuf,1,RLEN,stdin));
return (ob==ib)?EOF:*ib++;
}
#define gc getchar
inline int read(){
char ch=gc();
int res=0,f=1;
while(!isdigit(ch))f^=ch=='-',ch=gc();
while(isdigit(ch))res=(res+(res<<2)<<1)+(ch^48),ch=gc();
return f?res:-res;
}
#define ll long long
#define re register
#define pii pair<int,int>
#define pic pair<int,char>
#define fi first
#define se second
#define pb push_back
#define cs const
#define bg begin
#define poly vector<int>
template<class T>inline void chemx(T &a,T b){a<b?a=b:0;}
template<class T>inline void chemn(T &a,T b){a>b?a=b:0;}
cs int N=100005;
struct mat{
ll a[4][4];
mat(){memset(a,127/3,sizeof(a));}
friend inline mat operator *(cs mat &a,cs mat &b){
mat c;
for(int i=0;i<4;i++)
for(int k=0;k<4;k++)
for(int j=0;j<4;j++)
chemn(c.a[i][j],a.a[i][k]+b.a[k][j]);
return c;
}
};
inline mat mksm(mat a,ll b){
mat res;
memset(res.a,0,sizeof(res.a));
for(;b;b>>=1,a=a*a)if(b&1)res=res*a;
return res;
}
namespace Sam{
cs int M=N<<1;
int nxt[M][4],fa[M],len[M],tot,f[M][4],last;
inline void init(){
last=tot=1;
}
inline void insert(int c){
int cur=++tot,p=last;last=cur;
len[cur]=len[p]+1;
for(;p&&!nxt[p][c];p=fa[p])nxt[p][c]=cur;
if(!p)fa[cur]=1;
else{
int q=nxt[p][c];
if(len[p]+1==len[q])fa[cur]=q;
else{
int clo=++tot;
memcpy(nxt[clo],nxt[q],sizeof(nxt[q]));
fa[clo]=fa[q],len[clo]=len[p]+1;
for(;p&&nxt[p][c]==q;p=fa[p])nxt[p][c]=clo;
fa[q]=fa[cur]=clo;
}
}
}
int vis[M];
void dfs(int u){
if(vis[u])return;
vis[u]=1;
for(int i=0;i<4;i++){
int v=nxt[u][i];
if(!v)f[u][i]=1;
else{
dfs(v);
for(int j=0;j<4;j++)
chemn(f[u][j],f[v][j]+1);
}
}
}
inline void build(char *s){
init();
for(int i=1,len=strlen(s+1);i<=len;i++)insert(s[i]-'A');
memset(f,127/3,sizeof(f)),dfs(1);
}
mat now;
inline bool check(ll t,ll mx){
mat v=mksm(now,t);
ll res=2e18;
for(int i=0;i<4;i++)
for(int j=0;j<4;j++)
chemn(res,v.a[i][j]);
return res>=mx;
}
inline void calc(ll n){
for(int i=0;i<4;i++)
for(int j=0;j<4;j++)
if(nxt[1][i])now.a[i][j]=f[nxt[1][i]][j];
ll l=1,r=n,res=l;
while(l<=r){
ll mid=(l+r)>>1;
if(check(mid,n))r=mid-1,res=mid;
else l=mid+1;
}
cout<<res<<'
';
}
}
ll n;
char s[N];
int main(){
scanf("%lld",&n);
scanf("%s",s+1);
Sam::build(s);
Sam::calc(n);
}