QOJ.ac
QOJ
ID | Submission ID | Problem | Hacker | Owner | Result | Submit time | Judge time |
---|---|---|---|---|---|---|---|
#1072 | #678872 | #9522. A Simple String Problem | ucup-team159 | ucup-team087 | Failed. | 2024-10-27 12:28:21 | 2024-10-27 12:28:22 |
Details
Extra Test:
Accepted
time: 0ms
memory: 3720kb
input:
1 a b
output:
0
result:
ok single line: '0'
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#678872 | #9522. A Simple String Problem | ucup-team087# | WA | 398ms | 147452kb | C++23 | 23.4kb | 2024-10-26 16:20:15 | 2024-10-27 18:37:28 |
answer
#ifndef LOCAL
#pragma GCC optimize ("Ofast")
#pragma GCC optimize ("unroll-loops")
#endif
#include <bits/stdc++.h>
using namespace std;
using ll=long long;
#define int ll
bool dbg=false;
#define rng(i,a,b) for(int i=int(a);i<int(b);i++)
#define rep(i,b) rng(i,0,b)
#define gnr(i,a,b) for(int i=int(b)-1;i>=int(a);i--)
#define per(i,b) gnr(i,0,b)
#define pb push_back
#define eb emplace_back
#define a first
#define b second
#define bg begin()
#define ed end()
#define all(x) x.bg,x.ed
#define si(x) int(x.size())
#ifdef LOCAL
#define dmp(x) cerr<<__LINE__<<" "<<#x<<" "<<x<<endl
#else
#define dmp(x) void(0)
#endif
template<class t,class u> bool chmax(t&a,u b){if(a<b){a=b;return true;}else return false;}
template<class t,class u> bool chmin(t&a,u b){if(b<a){a=b;return true;}else return false;}
template<class t> using vc=vector<t>;
template<class t> using vvc=vc<vc<t>>;
using pi=pair<int,int>;
using vi=vc<int>;
using vvi=vc<vc<int>>;
template<class t,class u>
ostream& operator<<(ostream& os,const pair<t,u>& p){
return os<<"{"<<p.a<<","<<p.b<<"}";
}
template<class t> ostream& operator<<(ostream& os,const vc<t>& v){
os<<"{";
for(auto e:v)os<<e<<",";
return os<<"}";
}
#define mp make_pair
#define mt make_tuple
#define one(x) memset(x,-1,sizeof(x))
#define zero(x) memset(x,0,sizeof(x))
#ifdef LOCAL
void dmpr(ostream&os){os<<endl;}
template<class T,class... Args>
void dmpr(ostream&os,const T&t,const Args&... args){
os<<t<<" ";
dmpr(os,args...);
}
#define dmp2(...) dmpr(cerr,__LINE__,##__VA_ARGS__)
#else
#define dmp2(...) void(0)
#endif
using uint=unsigned;
using ull=unsigned long long;
template<class t,size_t n>
ostream& operator<<(ostream&os,const array<t,n>&a){
return os<<vc<t>(all(a));
}
ll rand_int(ll l, ll r) { //[l, r]
//#ifdef LOCAL
static mt19937_64 gen;
/*#else
static mt19937_64 gen(chrono::steady_clock::now().time_since_epoch().count());
#endif*/
return uniform_int_distribution<ll>(l, r)(gen);
}
ll rand_int(ll k){ //[0,k)
return rand_int(0,k-1);
}
string rand_string(int n,char lw,char up){
string s(n,'?');
rep(i,n)s[i]=rand_int(lw,up);
return s;
}
int current_run_id,run_batch_size=1000;
int calc_random_limit(){
return current_run_id/run_batch_size+1;
}
template<class t>
void generate_single(t&a){
a=rand_int(1,calc_random_limit());
}
void generate_single(string&a){
int n;generate_single(n);
a=rand_string(n,'a','b');
}
template<class t,class u>
void generate_single(pair<t,u>&a){
generate_single(a.a);
generate_single(a.b);
}
//https://trap.jp/post/1224/
template<class... Args>
void input(Args&... a){
if(dbg){
(generate_single(a),...);
}else{
#ifdef USE_FAST_IO
sc.read(a...);
#else
(cin >> ... >> a);
#endif
}
}
#define INT(...) int __VA_ARGS__;input(__VA_ARGS__)
#define LL(...) ll __VA_ARGS__;input(__VA_ARGS__)
#define ULL(...) ull __VA_ARGS__;input(__VA_ARGS__)
#define STR(...) string __VA_ARGS__;input(__VA_ARGS__)
#define CHR(...) char __VA_ARGS__;input(__VA_ARGS__)
#define DBL(...) double __VA_ARGS__;input(__VA_ARGS__)
#define LD(...) ld __VA_ARGS__;input(__VA_ARGS__)
#define overload3(a,b,c,d,...) d
#define VI2(name,size) vi name(size);rep(i_##name,size)input(name[i_##name]);
#define VI3(name,size,offset) vi name(size);rep(i_##name,size)input(name[i_##name]),name[i_##name]+=offset;
#define VI(...) overload3(__VA_ARGS__,VI3,VI2)(__VA_ARGS__)
#define VPI(name,size) vc<pi> name(size);rep(i_##name,size)input(name[i_##name]);
#define VVI(name,sizeN,sizeM) vvi name(sizeN,vi(sizeM));\
rep(i_##name,sizeN)rep(j_##name,sizeM)input(name[i_##name][j_##name]);
#define VS(name,size) vc<string> name(size);rep(i_##name,size)input(name[i_##name]);
#define overload5(a,b,c,d,e,f,...) f
#define VVC4(type,name,sizeN,sizeM) vvc<type> name(sizeN,vc<type>(sizeM));
#define VVC5(type,name,sizeN,sizeM,ini) vvc<type> name(sizeN,vc<type>(sizeM,ini));
#define VVC(...) overload5(__VA_ARGS__,VVC5,VVC4)(__VA_ARGS__)
template<class T>
T vvvc(T v){
return v;
}
template<class T,class...Args>
auto vvvc(int n,T v,Args...args){
return vector(n,vvvc(v,args...));
}
template<int i,class T>
void print_tuple(ostream&,const T&){
}
template<int i,class T,class H,class ...Args>
void print_tuple(ostream&os,const T&t){
if(i)os<<",";
os<<get<i>(t);
print_tuple<i+1,T,Args...>(os,t);
}
template<class ...Args>
ostream& operator<<(ostream&os,const tuple<Args...>&t){
os<<"{";
print_tuple<0,tuple<Args...>,Args...>(os,t);
return os<<"}";
}
void printsuc(int suc){
#ifdef USE_FAST_IO
if(suc==1)pr.write('\n');
if(suc==2)pr.write(' ');
#else
if(suc==1){
if(dbg)cout<<endl;
else{
#ifdef LOCAL
cout<<endl;
#else
cout<<"\n";
#endif
}
}
if(suc==2)
cout<<" ";
#endif
}
template<class t>
void print_single(t x,int suc=1){
#ifdef USE_FAST_IO
pr.write(x);
#else
cout<<x;
#endif
printsuc(suc);
}
template<class t,class u>
void print_single(const pair<t,u>&p,int suc=1){
print_single(p.a,2);
print_single(p.b,suc);
}
template<class T>
void print_single(const vector<T>&v,int suc=1){
rep(i,v.size())
print_single(v[i],i==int(v.size())-1?3:2);
printsuc(suc);
}
template<class T,size_t N>
void print_single(const array<T,N>&v,int suc=1){
rep(i,N)
print_single(v[i],i==int(N)-1?3:2);
printsuc(suc);
}
template<class T>
void print(const T&t){
print_single(t);
}
template<class T,class ...Args>
void print(const T&t,const Args&...args){
print_single(t,2);
print(args...);
}
template<class T>
void printvv(const vvc<T>&vs){
for(const auto&row:vs)print(row);
}
string readString(){
string s;
cin>>s;
return s;
}
template<class T>
T sq(const T& t){
return t*t;
}
void YES(bool ex=true){
cout<<"YES\n";
if(ex)exit(0);
#ifdef LOCAL
cout.flush();
#endif
}
void NO(bool ex=true){
cout<<"NO\n";
if(ex)exit(0);
#ifdef LOCAL
cout.flush();
#endif
}
void Yes(bool ex=true){
cout<<"Yes\n";
if(ex)exit(0);
#ifdef LOCAL
cout.flush();
#endif
}
void No(bool ex=true){
cout<<"No\n";
if(ex)exit(0);
#ifdef LOCAL
cout.flush();
#endif
}
//#define CAPITAL
/*
void yes(bool ex=true){
#ifdef CAPITAL
cout<<"YES"<<"\n";
#else
cout<<"Yes"<<"\n";
#endif
if(ex)exit(0);
#ifdef LOCAL
cout.flush();
#endif
}
void no(bool ex=true){
#ifdef CAPITAL
cout<<"NO"<<"\n";
#else
cout<<"No"<<"\n";
#endif
if(ex)exit(0);
#ifdef LOCAL
cout.flush();
#endif
}*/
void possible(bool ex=true){
#ifdef CAPITAL
cout<<"POSSIBLE"<<"\n";
#else
cout<<"Possible"<<"\n";
#endif
if(ex)exit(0);
#ifdef LOCAL
cout.flush();
#endif
}
void impossible(bool ex=true){
#ifdef CAPITAL
cout<<"IMPOSSIBLE"<<"\n";
#else
cout<<"Impossible"<<"\n";
#endif
if(ex)exit(0);
#ifdef LOCAL
cout.flush();
#endif
}
constexpr ll ten(int n){
return n==0?1:ten(n-1)*10;
}
const ll infLL=LLONG_MAX/3;
#ifdef int
const int inf=infLL;
#else
const int inf=INT_MAX/2-100;
#endif
int topbit(signed t){
return t==0?-1:31-__builtin_clz(t);
}
int topbit(ll t){
return t==0?-1:63-__builtin_clzll(t);
}
int topbit(ull t){
return t==0?-1:63-__builtin_clzll(t);
}
int botbit(signed a){
return a==0?32:__builtin_ctz(a);
}
int botbit(ll a){
return a==0?64:__builtin_ctzll(a);
}
int botbit(ull a){
return a==0?64:__builtin_ctzll(a);
}
int popcount(signed t){
return __builtin_popcount(t);
}
int popcount(ll t){
return __builtin_popcountll(t);
}
int popcount(ull t){
return __builtin_popcountll(t);
}
int bitparity(ll t){
return __builtin_parityll(t);
}
bool ispow2(int i){
return i&&(i&-i)==i;
}
ll mask(int i){
return (ll(1)<<i)-1;
}
ull umask(int i){
return (ull(1)<<i)-1;
}
ll minp2(ll n){
if(n<=1)return 1;
else return ll(1)<<(topbit(n-1)+1);
}
bool inc(int a,int b,int c){
return a<=b&&b<=c;
}
template<class S> void mkuni(S&v){
sort(all(v));
v.erase(unique(all(v)),v.ed);
}
template<class t> bool isuni(vc<t> v){
int s=si(v);
mkuni(v);
return si(v)==s;
}
template<class t>
void myshuffle(vc<t>&a){
rep(i,si(a))swap(a[i],a[rand_int(0,i)]);
}
template<class S,class u>
int lwb(const S&v,const u&a){
return lower_bound(all(v),a)-v.bg;
}
template<class t,class u>
bool bis(const vc<t>&v,const u&a){
return binary_search(all(v),a);
}
//VERIFY: yosupo
//KUPC2017J
//AOJDSL1A
//without rank
struct unionfind{
vi p,s;
int c;
unionfind(int n):p(n,-1),s(n,1),c(n){}
void clear(){
fill(all(p),-1);
fill(all(s),1);
c=si(p);
}
int find(int a){
return p[a]==-1?a:(p[a]=find(p[a]));
}
//set b to a child of a
bool unite(int a,int b){
a=find(a);
b=find(b);
if(a==b)return false;
p[b]=a;
s[a]+=s[b];
c--;
return true;
}
bool same(int a,int b){
return find(a)==find(b);
}
int sz(int a){
return s[find(a)];
}
};
vvc<int> readGraph(int n,int m){
vvc<int> g(n);
rep(i,m){
int a,b;
cin>>a>>b;
//sc.read(a,b);
a--;b--;
g[a].pb(b);
g[b].pb(a);
}
return g;
}
vvc<int> rand_tree(int n){
vvc<int> t(n);
unionfind uf(n);
while(uf.c>1){
int a=rand_int(n);
int b=rand_int(n);
if(uf.unite(a,b)){
t[a].pb(b);
t[b].pb(a);
}
}
return t;
}
vvc<int> readTree(int n){
if(dbg){
return rand_tree(n);
}else{
return readGraph(n,n-1);
}
}
vi readRooted(int n){
assert(!dbg);
vi par(n,-1);
rng(i,1,n){
input(par[i]);
par[i]--;
assert(inc(0,par[i],i-1));
}
return par;
}
void printTree(const vvc<int> t){
int n=si(t);
int degsum=0;
rep(i,n)degsum+=si(t[i]);
if(degsum==n-1){
//directed
rep(i,si(t))for(auto j:t[i]){
print(i+1,j+1);
}
}else if(degsum==2*(n-1)){
//undirected
rep(i,si(t))for(auto j:t[i])if(i<j){
print(i+1,j+1);
}
}else{
assert(false);
}
}
template<class t>
vc<t> presum(const vc<t>&a){
vc<t> s(si(a)+1);
rep(i,si(a))s[i+1]=s[i]+a[i];
return s;
}
vc<ll> presum(const vi&a){
vc<ll> s(si(a)+1);
rep(i,si(a))s[i+1]=s[i]+a[i];
return s;
}
//BIT で数列を管理するときに使う (CF850C)
template<class t>
vc<t> predif(vc<t> a){
gnr(i,1,si(a))a[i]-=a[i-1];
return a;
}
template<class t>
vvc<ll> imos(const vvc<t>&a){
int n=si(a),m=si(a[0]);
vvc<ll> b(n+1,vc<ll>(m+1));
rep(i,n)rep(j,m)
b[i+1][j+1]=b[i+1][j]+b[i][j+1]-b[i][j]+a[i][j];
return b;
}
//verify してないや
void transvvc(int&n,int&m){
swap(n,m);
}
template<class t,class... Args>
void transvvc(int&n,int&m,vvc<t>&a,Args&...args){
assert(si(a)==n);
vvc<t> b(m,vi(n));
rep(i,n){
assert(si(a[i])==m);
rep(j,m)b[j][i]=a[i][j];
}
a.swap(b);
transvvc(n,m,args...);
}
//CF854E
void rotvvc(int&n,int&m){
swap(n,m);
}
template<class t,class... Args>
void rotvvc(int&n,int&m,vvc<t>&a,Args&...args){
assert(si(a)==n);
vvc<t> b(m,vi(n));
rep(i,n){
assert(si(a[i])==m);
rep(j,m)b[m-1-j][i]=a[i][j];
}
a.swap(b);
rotvvc(n,m,args...);
}
//ソートして i 番目が idx[i]
//CF850C
template<class t>
vi sortidx(const vc<t>&a){
int n=si(a);
vi idx(n);iota(all(idx),0);
sort(all(idx),[&](int i,int j){return a[i]<a[j];});
return idx;
}
//vs[i]=a[idx[i]]
//例えば sortidx で得た idx を使えば単にソート列になって返ってくる
//CF850C
template<class t>
vc<t> a_idx(const vc<t>&a,const vi&idx){
int n=si(a);
assert(si(idx)==n);
vc<t> vs(n);
rep(i,n)vs[i]=a[idx[i]];
return vs;
}
//CF850C
vi invperm(const vi&p){
int n=si(p);
vi q(n);
rep(i,n)q[p[i]]=i;
return q;
}
template<class t,class s=t>
s SUM(const vc<t>&a){
return accumulate(all(a),s(0));
}
template<class t,size_t K,class s=t>
s SUM(const array<t,K>&a){
return accumulate(all(a),s(0));
}
template<class t>
t MAX(const vc<t>&a){
return *max_element(all(a));
}
template<class t>
pair<t,int> MAXi(const vc<t>&a){
auto itr=max_element(all(a));
return mp(*itr,itr-a.bg);
}
template<class A>
auto MIN(const A&a){
return *min_element(all(a));
}
template<class t>
pair<t,int> MINi(const vc<t>&a){
auto itr=min_element(all(a));
return mp(*itr,itr-a.bg);
}
vi vid(int n){
vi res(n);iota(all(res),0);
return res;
}
template<class S>
void soin(S&s){
sort(all(s));
}
template<class S,class F>
void soin(S&s,F&&f){
sort(all(s),forward<F>(f));
}
template<class S>
S soout(S s){
soin(s);
return s;
}
template<class S>
void rein(S&s){
reverse(all(s));
}
template<class S>
S reout(S s){
rein(s);
return s;
}
template<class t,class u>
pair<t,u>&operator+=(pair<t,u>&a,pair<t,u> b){
a.a+=b.a;a.b+=b.b;return a;}
template<class t,class u>
pair<t,u>&operator-=(pair<t,u>&a,pair<t,u> b){
a.a-=b.a;a.b-=b.b;return a;}
template<class t,class u>
pair<t,u> operator+(pair<t,u> a,pair<t,u> b){return mp(a.a+b.a,a.b+b.b);}
template<class t,class u>
pair<t,u> operator-(pair<t,u> a,pair<t,u> b){return mp(a.a-b.a,a.b-b.b);}
template<class t,class u,class v>
pair<t,u>&operator*=(pair<t,u>&a,v b){
a.a*=b;a.b*=b;return a;}
template<class t,class u,class v>
pair<t,u> operator*(pair<t,u> a,v b){return a*=b;}
template<class t,class u>
pair<t,u> operator-(pair<t,u> a){return mp(-a.a,-a.b);}
namespace std{
template<class t,class u>
istream&operator>>(istream&is,pair<t,u>&a){
return is>>a.a>>a.b;
}
}
template<class t>
t gpp(vc<t>&vs){
assert(si(vs));
t res=move(vs.back());
vs.pop_back();
return res;
}
template<class t,class u>
void pb(vc<t>&a,const vc<u>&b){
a.insert(a.ed,all(b));
}
template<class t,class...Args>
vc<t> cat(vc<t> a,Args&&...b){
(pb(a,forward<Args>(b)),...);
return a;
}
template<class t,class u>
vc<t>& operator+=(vc<t>&a,u x){
for(auto&v:a)v+=x;
return a;
}
template<class t,class u>
vc<t> operator+(vc<t> a,u x){
return a+=x;
}
template<class t>
vc<t>& operator+=(vc<t>&a,const vc<t>&b){
a.resize(max(si(a),si(b)));
rep(i,si(b))a[i]+=b[i];
return a;
}
template<class t>
vc<t> operator+(const vc<t>&a,const vc<t>&b){
vc<t> c(max(si(a),si(b)));
rep(i,si(a))c[i]+=a[i];
rep(i,si(b))c[i]+=b[i];
return c;
}
template<class t,class u>
vc<t>& operator-=(vc<t>&a,u x){
for(auto&v:a)v-=x;
return a;
}
template<class t,class u>
vc<t> operator-(vc<t> a,u x){
return a-=x;
}
template<class t,class u>
vc<t>& operator*=(vc<t>&a,u x){
for(auto&v:a)v*=x;
return a;
}
template<class t,class u>
vc<t> operator*(vc<t> a,u x){
return a*=x;
}
template<class t,class u>
vc<t>& operator/=(vc<t>&a,u x){
for(auto&v:a)v/=x;
return a;
}
template<class t,class u>
vc<t> operator/(vc<t> a,u x){
return a/=x;
}
template<class t>
vc<t>& operator<<=(vc<t>&a,int k){
assert(k>=0);
a.insert(a.bg,k,t(0));
return a;
}
template<class t>
vc<t> operator<<(vc<t> a,int k){
return a<<=k;
}
template<class t>
vc<t>& operator>>=(vc<t>&a,int k){
if(si(a)<=k)a.clear();
else a.erase(a.bg,a.bg+k);
return a;
}
template<class t>
vc<t> operator>>(vc<t> a,int k){
return a>>=k;
}
template<class t,class u>
void remval(vc<t>&a,const u&v){
a.erase(remove(all(a),v),a.ed);
}
//消した要素の個数を返してくれる
//UCUP 2-8-F
template<class t,class F>
int remif(vc<t>&a,F f){
auto itr=remove_if(all(a),f);
int res=a.ed-itr;
a.erase(itr,a.ed);
return res;
}
template<class t>
void rempos(vc<t>&a,int i){
assert(inc(0,i,si(a)-1));
a.erase(a.bg+i);
}
template<class VS,class u>
void fila(VS&vs,const u&a){
fill(all(vs),a);
}
template<class t,class u>
int findid(const vc<t>&vs,const u&a){
auto itr=find(all(vs),a);
if(itr==vs.ed)return -1;
else return itr-vs.bg;
}
template<class t>
void rtt(vc<t>&vs,int i){
rotate(vs.bg,vs.bg+i,vs.ed);
}
//Multiuni2023-8 C
//f(lw)=false,...,f(n-1)=false,f(n)=true,...,f(up)=true,
//のときに n を返す
template<class F>
int find_min_true(int lw,int up,F f){
while(up-lw>1){
const int mid=(lw+up)/2;
if(f(mid))up=mid;
else lw=mid;
}
return up;
}
//f(lw)=true,f(up)=false
template<class F>
int find_max_true(int lw,int up,F f){
while(up-lw>1){
const int mid=(lw+up)/2;
if(f(mid))lw=mid;
else up=mid;
}
return lw;
}
template<class t> using pqmin=priority_queue<t,vc<t>,greater<t>>;
template<class t> using pqmax=priority_queue<t>;
using T=tuple<int,int,int>;
//O(N+max(A)) なので座標圧縮してから動かしてください
//Verify yosupo (N=500000,string,43ms)
template<class t>vi sais(t a){
int n=si(a),m=*max_element(all(a))+1;
vi pos(m+1),x(m),sa(n),val(n),lms;
for(auto c:a)pos[c+1]++;
rep(i,m)pos[i+1]+=pos[i];
vc<bool> s(n);
per(i,n-1)s[i]=a[i]!=a[i+1]?a[i]<a[i+1]:s[i+1];
auto ind=[&](const vi&ls){
fill(all(sa),-1);
auto L=[&](int i){if(i>=0&&!s[i])sa[x[a[i]]++]=i;};
auto S=[&](int i){if(i>=0&& s[i])sa[--x[a[i]]]=i;};
rep(i,m)x[i]=pos[i+1];
per(i,si(ls))S(ls[i]);
rep(i,m)x[i]=pos[i];
L(n-1);
rep(i,n)L(sa[i]-1);
rep(i,m)x[i]=pos[i+1];
per(i,n)S(sa[i]-1);
};
auto ok=[&](int i){return i==n||(!s[i-1]&&s[i]);};
auto same=[&](int i,int j){
do{
if(a[i++]!=a[j++])return false;
}while(!ok(i)&&!ok(j));
return ok(i)&&ok(j);
};
rng(i,1,n)if(ok(i))lms.pb(i);
ind(lms);
if(si(lms)){
int p=-1,w=0;
for(auto v:sa)if(v&&ok(v)){
if(p!=-1&&same(p,v))w--;
val[p=v]=w++;
}
vi b=lms;
for(auto&v:b)v=val[v];
b=sais(b);
for(auto&v:b)v=lms[v];
ind(b);
}
return sa;
}
struct SA{
int n;
vi sa,as,lcp;
template<class t> SA(t s):n(si(s)),as(n),lcp(n-1){
{//座標圧縮,値域が小さいなら skip 可
auto vs=s;mkuni(vs);
for(auto&v:s)v=lwb(vs,v);
}
sa=sais(s);
//as
rep(i,n)as[sa[i]]=i;
//lcp
int w=0;
for(auto i:as){
if(w)w--;
if(i<n-1){
while(max(sa[i],sa[i+1])+w<n&&s[sa[i]+w]==s[sa[i+1]+w]) w++;
lcp[i]=w;
}
}
}
};
//VERIFY: yosupo
//AOJGRL5C
template<class t,class u>
struct sparsetable{
vvc<t> a;
u f;
const t id;
sparsetable(const vc<t>& d,u ff,t w):f(ff),id(w){
if(d.empty())return;
int n=d.size(),h=topbit(n);
a.resize(h+1);
a[0]=d;
rng(j,1,h+1){
a[j].resize(n-(1<<j)+1);
rep(i,n-(1<<j)+1)
a[j][i]=f(a[j-1][i],a[j-1][i+(1<<(j-1))]);
}
}
t get(int b,int e){
assert(b<=e);
if(b==e)return id;
int d=topbit(e-b);
return f(a[d][b],a[d][e-(1<<d)]);
}
};
const auto imin=[](int a,int b){
return min(a,b);
};
using minst=sparsetable<int,decltype(imin)>;
auto getminst(vi a){return minst(a,imin,inf);}
const auto imax=[](int a,int b){
return max(a,b);
};
using maxst=sparsetable<int,decltype(imax)>;
auto getmaxst(vi a){return maxst(a,imax,-inf);}
const auto pimax=[](pi a,pi b){
return max(a,b);
};
using pimaxst=sparsetable<pi,decltype(pimax)>;
const auto pimin=[](pi a,pi b){
return min(a,b);
};
using piminst=sparsetable<pi,decltype(pimin)>;
//Xmas2012B
template<class S>
struct string_cmp{
S s;
int n;
SA sa;
minst t;
string_cmp(const S&ss):s(ss),n(si(s)),sa(s),t(sa.lcp,imin,inf){}
int getlcp(int i,int j){
if(i==n||j==n)return 0;
if(i==j)return n-i;
i=sa.as[i];
j=sa.as[j];
if(i>j)swap(i,j);
return t.get(i,j);
}
int cmpchar(int i,int j){
assert(0<=i&&i<n);
assert(0<=j&&j<n);
assert(s[i]!=s[j]);
return s[i]<s[j]?-1:1;
}
//[a,b)<[c,d)-> -1
//same -> 0
//[a,b)>[c,d) -> 1
int cmp(int a,int b,int c,int d){
int len=min({getlcp(a,c),b-a,d-c});
if(a+len==b&&c+len==d)return 0;
if(a+len==b)return -1;
if(c+len==d)return 1;
return cmpchar(a+len,c+len);
}
//ABC240H
int cmp(pi a,pi b){
return cmp(a.a,a.b,b.a,b.b);
}
int cmp_samelen(int a,int b,int len){
return cmp(a,a+len,b,b+len);
}
//[l,r) のリストを受け取り,それらを連結してできる文字列の比較をする
//リストの長さ 2 の場合は verify (Xmas2012 B)
//UCUP 3-10-B
int cmp_list(const vc<pi>&a,const vc<pi>&b){
assert(si(a));
assert(si(b));
int i=0,j=0;
pi u=a[0],v=b[0];
while(1){
while(i<si(a)&&u.a==u.b){
if(++i<si(a))u=a[i];
}
while(j<si(b)&&v.a==v.b){
if(++j<si(b))v=b[j];
}
if(i==si(a)&&j==si(b))return 0;
if(i==si(a))return -1;
if(j==si(b))return 1;
int k=min(u.b-u.a,v.b-v.a);
int x=cmp_samelen(u.a,v.a,k);
if(x)return x;
u.a+=k;
v.a+=k;
}
assert(0);
}
//[l,r) のリストを受け取り,それらを連結してできる文字列の LCP を求める
//UCUP 2-17-H
int lcp_list(vc<pi> a,vc<pi> b){
int i=0,j=0,res=0;
while(1){
while(i<si(a)&&a[i].a==a[i].b)i++;
while(j<si(b)&&b[j].a==b[j].b)j++;
if(i==si(a)||j==si(b))return res;
int k=min(a[i].b-a[i].a,b[j].b-b[j].a);
int x=getlcp(a[i].a,b[j].a);
if(x<k)return res+x;
res+=k;
a[i].a+=k;
b[j].a+=k;
}
assert(0);
}
//UCUP 2-24-E
//s[i,i+len) = s[j,j+len) が一致するような j の範囲
//範囲というのは SA 上での範囲
//TLE したので segtree で代用 (UCUP 2-24-E)
pi common_range(int i,int len){
assert(inc(0,i,n-1));
i=sa.as[i];
int l=find_min_true(-1,i,[&](int j){
return t.get(j,i)>=len;
});
int r=find_max_true(i,n,[&](int j){
return t.get(i,j)>=len;
})+1;
return pi(l,r);
}
};
//Petrozavodsk 2019w Day9 G
//Petrozavodsk 2020S Day4 G
//aba->121
template<class S>
vi manacher(const S&s){
int n=s.size();
vi v(n);
int j=0;
rep(i,n){
int k=j*2-i;
if(k>=0&&i+v[k]<j+v[j])
v[i]=v[k];
else{
v[i]=j+v[j]-i;
j=i;
while(i+v[i]<n&&i-v[i]>=0&&s[i-v[i]]==s[i+v[i]])
v[i]++;
}
}
return v;
}
template<class S>
vi manacher_even(const S&s,int none){
S t;
t.reserve(si(s)*2+1);
t.pb(none);
for(auto c:s){
t.pb(c);
t.pb(none);
}
vi a=manacher(t),b;
rep(i,si(s)+1)
b.pb(a[i*2]/2);
return b;
}
//XXII Opencup GP of Yuquan
template<class S>
vi manacher_oddeven(const S&s,int none){
S t;
t.reserve(si(s)*2-1);
rep(i,si(s)){
t.pb(s[i]);
if(i+1<si(s))t.pb(none);
}
return manacher(t);
}
//XXII Opencup GP of Yuquan
bool ispal(const vi&t,int l,int r){
int mid=(l+r-1);
return t[mid]>=r-l;
}
//UCUP 2-27-G
//aabaa -> [0,1,2,1,0,5,0,1,2,1,0]
template<class S>
vi diameter(const S&s,int none){
int n=si(s);
S t;
t.reserve(n*2+1);
t.pb(none);
rep(i,n){
t.pb(s[i]);
t.pb(none);
}
return manacher(t)-1;
}
void slv(){
INT(n);
STR(s);
STR(t);
s=s+"?"s;
t="?"s+t;
n++;
string_cmp sc(s+'1'+t+'2'+reout(s)+'3'+reout(t));
int ans=0;
auto work=[&](int l,int r){
assert(0<=l&&l<r&&r<=n);
{
int x=sc.getlcp((n+1)*2+(n-l),(n+1)*2+(n-r));
int y=sc.getlcp((n+1)*0+l,(n+1)*0+r);
int z=sc.getlcp((n+1)*0+l+y,(n+1)*1+r+y);
if(x+y+z>=r-l){
chmax(ans,(r-l)*2);
return;
}
}
{
int x=sc.getlcp((n+1)*2+(n-l),(n+1)*3+(n-r));
int y=sc.getlcp((n+1)*0+l,(n+1)*1+r);
if(x+y>=r-l){
chmax(ans,(r-l)*2);
return;
}
}
{
int x=sc.getlcp((n+1)*3+(n-l),(n+1)*3+(n-r));
int y=sc.getlcp((n+1)*2+(n-(l-x)),(n+1)*3+(n-(r-x)));
int z=sc.getlcp((n+1)*1+l,(n+1)*1+r);
if(x+y+z>=r-l){
chmax(ans,(r-l)*2);
return;
}
}
};
auto dfs=[&](auto self,int l,int r)->void{
if(r-l<=1)return;
int m=(l+r)/2;
rng(i,l+1,m)work(i,m);
rng(i,m+1,r)work(m,i);
self(self,l,m);
self(self,m,r);
};
dfs(dfs,-1,n+1);
print(ans);
}
signed main(signed argc,char*argv[]){
if(argc>1&&strcmp(argv[1],"D")==0)dbg=true;
cin.tie(0);
ios::sync_with_stdio(0);
cout<<fixed<<setprecision(20);
if(dbg){
while(1){
if(current_run_id%run_batch_size==0){
cerr<<"Current Run "<<current_run_id<<endl;
}
slv();
current_run_id++;
}
}else{
//int t;cin>>t;rep(_,t)
slv();
}
}