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test_atcoder/abc240ex.test.cpp
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- Last update: 2024-03-29 11:46:13+09:00
- Problem: https://atcoder.jp/contests/abc240/tasks/abc240_Ex
Depends on
- alg/monoid/max.hpp
- alg/monoid/min.hpp
- ds/segtree/segtree.hpp
- ds/sparse_table/sparse_table.hpp
- my_template.hpp
- other/io.hpp
- string/sort_substrings.hpp
- string/suffix_array.hpp
Code
#define PROBLEM "https://atcoder.jp/contests/abc240/tasks/abc240_Ex"
#include "my_template.hpp"
#include "other/io.hpp"
#include "string/sort_substrings.hpp"
#include "ds/segtree/segtree.hpp"
#include "alg/monoid/max.hpp"
void solve() {
LL(N);
STR(S);
ll LIM = 1;
while (LIM * LIM < 2 * N) LIM++;
LIM += 10;
chmin(LIM, N);
auto rank = sort_substrings(S, LIM);
// 文字列ランク -> (L, R)
ll mx = 0;
FOR(i, len(rank)) chmax(mx, MAX(rank[i]));
vvc<pair<int, int>> LR(mx + 1);
FOR_R(i, N) FOR(j, LIM + 1) {
int r = rank[i][j];
if (r != -1) LR[r].eb(i, i + j);
}
using Mono = Monoid_Max<int>;
SegTree<Mono> seg(N + 1);
seg.set(0, 0);
vc<int> DP(N + 1, -infty<int>);
DP[0] = 0;
FOR(rk, mx + 1) {
for (auto&& [L, R]: LR[rk]) {
ll x = 1 + seg.prod(0, L + 1);
if (DP[R] < x) seg.set(R, x);
chmax(DP[R], x);
}
}
print(seg.prod_all());
}
signed main() {
solve();
return 0;
}#line 1 "test_atcoder/abc240ex.test.cpp"
#define PROBLEM "https://atcoder.jp/contests/abc240/tasks/abc240_Ex"
#line 1 "my_template.hpp"
#if defined(LOCAL)
#include <my_template_compiled.hpp>
#else
// https://codeforces.com/blog/entry/96344
#pragma GCC optimize("Ofast,unroll-loops")
// いまの CF だとこれ入れると動かない？
// #pragma GCC target("avx2,popcnt")
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using u32 = unsigned int;
using u64 = unsigned long long;
using i128 = __int128;
using u128 = unsigned __int128;
using f128 = __float128;
template <class T>
constexpr T infty = 0;
template <>
constexpr int infty<int> = 1'000'000'000;
template <>
constexpr ll infty<ll> = ll(infty<int>) * infty<int> * 2;
template <>
constexpr u32 infty<u32> = infty<int>;
template <>
constexpr u64 infty<u64> = infty<ll>;
template <>
constexpr i128 infty<i128> = i128(infty<ll>) * infty<ll>;
template <>
constexpr double infty<double> = infty<ll>;
template <>
constexpr long double infty<long double> = infty<ll>;
using pi = pair<ll, ll>;
using vi = vector<ll>;
template <class T>
using vc = vector<T>;
template <class T>
using vvc = vector<vc<T>>;
template <class T>
using vvvc = vector<vvc<T>>;
template <class T>
using vvvvc = vector<vvvc<T>>;
template <class T>
using vvvvvc = vector<vvvvc<T>>;
template <class T>
using pq = priority_queue<T>;
template <class T>
using pqg = priority_queue<T, vector<T>, greater<T>>;
#define vv(type, name, h, ...) \
vector<vector<type>> name(h, vector<type>(__VA_ARGS__))
#define vvv(type, name, h, w, ...) \
vector<vector<vector<type>>> name( \
h, vector<vector<type>>(w, vector<type>(__VA_ARGS__)))
#define vvvv(type, name, a, b, c, ...) \
vector<vector<vector<vector<type>>>> name( \
a, vector<vector<vector<type>>>( \
b, vector<vector<type>>(c, vector<type>(__VA_ARGS__))))
// https://trap.jp/post/1224/
#define FOR1(a) for (ll _ = 0; _ < ll(a); ++_)
#define FOR2(i, a) for (ll i = 0; i < ll(a); ++i)
#define FOR3(i, a, b) for (ll i = a; i < ll(b); ++i)
#define FOR4(i, a, b, c) for (ll i = a; i < ll(b); i += (c))
#define FOR1_R(a) for (ll i = (a)-1; i >= ll(0); --i)
#define FOR2_R(i, a) for (ll i = (a)-1; i >= ll(0); --i)
#define FOR3_R(i, a, b) for (ll i = (b)-1; i >= ll(a); --i)
#define overload4(a, b, c, d, e, ...) e
#define overload3(a, b, c, d, ...) d
#define FOR(...) overload4(__VA_ARGS__, FOR4, FOR3, FOR2, FOR1)(__VA_ARGS__)
#define FOR_R(...) overload3(__VA_ARGS__, FOR3_R, FOR2_R, FOR1_R)(__VA_ARGS__)
#define FOR_subset(t, s) \
for (ll t = (s); t >= 0; t = (t == 0 ? -1 : (t - 1) & (s)))
#define all(x) x.begin(), x.end()
#define len(x) ll(x.size())
#define elif else if
#define eb emplace_back
#define mp make_pair
#define mt make_tuple
#define fi first
#define se second
#define stoi stoll
int popcnt(int x) { return __builtin_popcount(x); }
int popcnt(u32 x) { return __builtin_popcount(x); }
int popcnt(ll x) { return __builtin_popcountll(x); }
int popcnt(u64 x) { return __builtin_popcountll(x); }
int popcnt_mod_2(int x) { return __builtin_parity(x); }
int popcnt_mod_2(u32 x) { return __builtin_parity(x); }
int popcnt_mod_2(ll x) { return __builtin_parityll(x); }
int popcnt_mod_2(u64 x) { return __builtin_parityll(x); }
// (0, 1, 2, 3, 4) -> (-1, 0, 1, 1, 2)
int topbit(int x) { return (x == 0 ? -1 : 31 - __builtin_clz(x)); }
int topbit(u32 x) { return (x == 0 ? -1 : 31 - __builtin_clz(x)); }
int topbit(ll x) { return (x == 0 ? -1 : 63 - __builtin_clzll(x)); }
int topbit(u64 x) { return (x == 0 ? -1 : 63 - __builtin_clzll(x)); }
// (0, 1, 2, 3, 4) -> (-1, 0, 1, 0, 2)
int lowbit(int x) { return (x == 0 ? -1 : __builtin_ctz(x)); }
int lowbit(u32 x) { return (x == 0 ? -1 : __builtin_ctz(x)); }
int lowbit(ll x) { return (x == 0 ? -1 : __builtin_ctzll(x)); }
int lowbit(u64 x) { return (x == 0 ? -1 : __builtin_ctzll(x)); }
template <typename T>
T floor(T a, T b) {
return a / b - (a % b && (a ^ b) < 0);
}
template <typename T>
T ceil(T x, T y) {
return floor(x + y - 1, y);
}
template <typename T>
T bmod(T x, T y) {
return x - y * floor(x, y);
}
template <typename T>
pair<T, T> divmod(T x, T y) {
T q = floor(x, y);
return {q, x - q * y};
}
template <typename T, typename U>
T SUM(const vector<U> &A) {
T sm = 0;
for (auto &&a: A) sm += a;
return sm;
}
#define MIN(v) *min_element(all(v))
#define MAX(v) *max_element(all(v))
#define LB(c, x) distance((c).begin(), lower_bound(all(c), (x)))
#define UB(c, x) distance((c).begin(), upper_bound(all(c), (x)))
#define UNIQUE(x) \
sort(all(x)), x.erase(unique(all(x)), x.end()), x.shrink_to_fit()
template <typename T>
T POP(deque<T> &que) {
T a = que.front();
que.pop_front();
return a;
}
template <typename T>
T POP(pq<T> &que) {
T a = que.top();
que.pop();
return a;
}
template <typename T>
T POP(pqg<T> &que) {
T a = que.top();
que.pop();
return a;
}
template <typename T>
T POP(vc<T> &que) {
T a = que.back();
que.pop_back();
return a;
}
template <typename F>
ll binary_search(F check, ll ok, ll ng, bool check_ok = true) {
if (check_ok) assert(check(ok));
while (abs(ok - ng) > 1) {
auto x = (ng + ok) / 2;
(check(x) ? ok : ng) = x;
}
return ok;
}
template <typename F>
double binary_search_real(F check, double ok, double ng, int iter = 100) {
FOR(iter) {
double x = (ok + ng) / 2;
(check(x) ? ok : ng) = x;
}
return (ok + ng) / 2;
}
template <class T, class S>
inline bool chmax(T &a, const S &b) {
return (a < b ? a = b, 1 : 0);
}
template <class T, class S>
inline bool chmin(T &a, const S &b) {
return (a > b ? a = b, 1 : 0);
}
// ? は -1
vc<int> s_to_vi(const string &S, char first_char) {
vc<int> A(S.size());
FOR(i, S.size()) { A[i] = (S[i] != '?' ? S[i] - first_char : -1); }
return A;
}
template <typename T, typename U>
vector<T> cumsum(vector<U> &A, int off = 1) {
int N = A.size();
vector<T> B(N + 1);
FOR(i, N) { B[i + 1] = B[i] + A[i]; }
if (off == 0) B.erase(B.begin());
return B;
}
// stable sort
template <typename T>
vector<int> argsort(const vector<T> &A) {
vector<int> ids(len(A));
iota(all(ids), 0);
sort(all(ids),
[&](int i, int j) { return (A[i] == A[j] ? i < j : A[i] < A[j]); });
return ids;
}
// A[I[0]], A[I[1]], ...
template <typename T>
vc<T> rearrange(const vc<T> &A, const vc<int> &I) {
vc<T> B(len(I));
FOR(i, len(I)) B[i] = A[I[i]];
return B;
}
#endif
#line 1 "other/io.hpp"
#define FASTIO
#include <unistd.h>
// https://judge.yosupo.jp/submission/21623
namespace fastio {
static constexpr uint32_t SZ = 1 << 17;
char ibuf[SZ];
char obuf[SZ];
char out[100];
// pointer of ibuf, obuf
uint32_t pil = 0, pir = 0, por = 0;
struct Pre {
char num[10000][4];
constexpr Pre() : num() {
for (int i = 0; i < 10000; i++) {
int n = i;
for (int j = 3; j >= 0; j--) {
num[i][j] = n % 10 | '0';
n /= 10;
}
}
}
} constexpr pre;
inline void load() {
memcpy(ibuf, ibuf + pil, pir - pil);
pir = pir - pil + fread(ibuf + pir - pil, 1, SZ - pir + pil, stdin);
pil = 0;
if (pir < SZ) ibuf[pir++] = '\n';
}
inline void flush() {
fwrite(obuf, 1, por, stdout);
por = 0;
}
void rd(char &c) {
do {
if (pil + 1 > pir) load();
c = ibuf[pil++];
} while (isspace(c));
}
void rd(string &x) {
x.clear();
char c;
do {
if (pil + 1 > pir) load();
c = ibuf[pil++];
} while (isspace(c));
do {
x += c;
if (pil == pir) load();
c = ibuf[pil++];
} while (!isspace(c));
}
template <typename T>
void rd_real(T &x) {
string s;
rd(s);
x = stod(s);
}
template <typename T>
void rd_integer(T &x) {
if (pil + 100 > pir) load();
char c;
do
c = ibuf[pil++];
while (c < '-');
bool minus = 0;
if constexpr (is_signed<T>::value || is_same_v<T, i128>) {
if (c == '-') { minus = 1, c = ibuf[pil++]; }
}
x = 0;
while ('0' <= c) { x = x * 10 + (c & 15), c = ibuf[pil++]; }
if constexpr (is_signed<T>::value || is_same_v<T, i128>) {
if (minus) x = -x;
}
}
void rd(int &x) { rd_integer(x); }
void rd(ll &x) { rd_integer(x); }
void rd(i128 &x) { rd_integer(x); }
void rd(u32 &x) { rd_integer(x); }
void rd(u64 &x) { rd_integer(x); }
void rd(u128 &x) { rd_integer(x); }
void rd(double &x) { rd_real(x); }
void rd(long double &x) { rd_real(x); }
void rd(f128 &x) { rd_real(x); }
template <class T, class U>
void rd(pair<T, U> &p) {
return rd(p.first), rd(p.second);
}
template <size_t N = 0, typename T>
void rd_tuple(T &t) {
if constexpr (N < std::tuple_size<T>::value) {
auto &x = std::get<N>(t);
rd(x);
rd_tuple<N + 1>(t);
}
}
template <class... T>
void rd(tuple<T...> &tpl) {
rd_tuple(tpl);
}
template <size_t N = 0, typename T>
void rd(array<T, N> &x) {
for (auto &d: x) rd(d);
}
template <class T>
void rd(vc<T> &x) {
for (auto &d: x) rd(d);
}
void read() {}
template <class H, class... T>
void read(H &h, T &... t) {
rd(h), read(t...);
}
void wt(const char c) {
if (por == SZ) flush();
obuf[por++] = c;
}
void wt(const string s) {
for (char c: s) wt(c);
}
void wt(const char *s) {
size_t len = strlen(s);
for (size_t i = 0; i < len; i++) wt(s[i]);
}
template <typename T>
void wt_integer(T x) {
if (por > SZ - 100) flush();
if (x < 0) { obuf[por++] = '-', x = -x; }
int outi;
for (outi = 96; x >= 10000; outi -= 4) {
memcpy(out + outi, pre.num[x % 10000], 4);
x /= 10000;
}
if (x >= 1000) {
memcpy(obuf + por, pre.num[x], 4);
por += 4;
} else if (x >= 100) {
memcpy(obuf + por, pre.num[x] + 1, 3);
por += 3;
} else if (x >= 10) {
int q = (x * 103) >> 10;
obuf[por] = q | '0';
obuf[por + 1] = (x - q * 10) | '0';
por += 2;
} else
obuf[por++] = x | '0';
memcpy(obuf + por, out + outi + 4, 96 - outi);
por += 96 - outi;
}
template <typename T>
void wt_real(T x) {
ostringstream oss;
oss << fixed << setprecision(15) << double(x);
string s = oss.str();
wt(s);
}
void wt(int x) { wt_integer(x); }
void wt(ll x) { wt_integer(x); }
void wt(i128 x) { wt_integer(x); }
void wt(u32 x) { wt_integer(x); }
void wt(u64 x) { wt_integer(x); }
void wt(u128 x) { wt_integer(x); }
void wt(double x) { wt_real(x); }
void wt(long double x) { wt_real(x); }
void wt(f128 x) { wt_real(x); }
template <class T, class U>
void wt(const pair<T, U> val) {
wt(val.first);
wt(' ');
wt(val.second);
}
template <size_t N = 0, typename T>
void wt_tuple(const T t) {
if constexpr (N < std::tuple_size<T>::value) {
if constexpr (N > 0) { wt(' '); }
const auto x = std::get<N>(t);
wt(x);
wt_tuple<N + 1>(t);
}
}
template <class... T>
void wt(tuple<T...> tpl) {
wt_tuple(tpl);
}
template <class T, size_t S>
void wt(const array<T, S> val) {
auto n = val.size();
for (size_t i = 0; i < n; i++) {
if (i) wt(' ');
wt(val[i]);
}
}
template <class T>
void wt(const vector<T> val) {
auto n = val.size();
for (size_t i = 0; i < n; i++) {
if (i) wt(' ');
wt(val[i]);
}
}
void print() { wt('\n'); }
template <class Head, class... Tail>
void print(Head &&head, Tail &&... tail) {
wt(head);
if (sizeof...(Tail)) wt(' ');
print(forward<Tail>(tail)...);
}
// gcc expansion. called automaticall after main.
void __attribute__((destructor)) _d() { flush(); }
} // namespace fastio
using fastio::read;
using fastio::print;
using fastio::flush;
#define INT(...) \
int __VA_ARGS__; \
read(__VA_ARGS__)
#define LL(...) \
ll __VA_ARGS__; \
read(__VA_ARGS__)
#define U32(...) \
u32 __VA_ARGS__; \
read(__VA_ARGS__)
#define U64(...) \
u64 __VA_ARGS__; \
read(__VA_ARGS__)
#define STR(...) \
string __VA_ARGS__; \
read(__VA_ARGS__)
#define CHAR(...) \
char __VA_ARGS__; \
read(__VA_ARGS__)
#define DBL(...) \
double __VA_ARGS__; \
read(__VA_ARGS__)
#define VEC(type, name, size) \
vector<type> name(size); \
read(name)
#define VV(type, name, h, w) \
vector<vector<type>> name(h, vector<type>(w)); \
read(name)
void YES(bool t = 1) { print(t ? "YES" : "NO"); }
void NO(bool t = 1) { YES(!t); }
void Yes(bool t = 1) { print(t ? "Yes" : "No"); }
void No(bool t = 1) { Yes(!t); }
void yes(bool t = 1) { print(t ? "yes" : "no"); }
void no(bool t = 1) { yes(!t); }
#line 2 "string/suffix_array.hpp"
#line 2 "alg/monoid/min.hpp"
template <typename E>
struct Monoid_Min {
using X = E;
using value_type = X;
static constexpr X op(const X &x, const X &y) noexcept { return min(x, y); }
static constexpr X unit() { return infty<E>; }
static constexpr bool commute = true;
};
#line 2 "ds/sparse_table/sparse_table.hpp"
// 冪等なモノイドであることを仮定。disjoint sparse table より x 倍高速
template <class Monoid>
struct Sparse_Table {
using MX = Monoid;
using X = typename MX::value_type;
int n, log;
vvc<X> dat;
Sparse_Table() {}
Sparse_Table(int n) { build(n); }
template <typename F>
Sparse_Table(int n, F f) {
build(n, f);
}
Sparse_Table(const vc<X>& v) { build(v); }
void build(int m) {
build(m, [](int i) -> X { return MX::unit(); });
}
void build(const vc<X>& v) {
build(len(v), [&](int i) -> X { return v[i]; });
}
template <typename F>
void build(int m, F f) {
n = m, log = 1;
while ((1 << log) < n) ++log;
dat.resize(log);
dat[0].resize(n);
FOR(i, n) dat[0][i] = f(i);
FOR(i, log - 1) {
dat[i + 1].resize(len(dat[i]) - (1 << i));
FOR(j, len(dat[i]) - (1 << i)) {
dat[i + 1][j] = MX::op(dat[i][j], dat[i][j + (1 << i)]);
}
}
}
X prod(int L, int R) {
if (L == R) return MX::unit();
if (R == L + 1) return dat[0][L];
int k = topbit(R - L - 1);
return MX::op(dat[k][L], dat[k][R - (1 << k)]);
}
template <class F>
int max_right(const F check, int L) {
assert(0 <= L && L <= n && check(MX::unit()));
if (L == n) return n;
int ok = L, ng = n + 1;
while (ok + 1 < ng) {
int k = (ok + ng) / 2;
bool bl = check(prod(L, k));
if (bl) ok = k;
if (!bl) ng = k;
}
return ok;
}
template <class F>
int min_left(const F check, int R) {
assert(0 <= R && R <= n && check(MX::unit()));
if (R == 0) return 0;
int ok = R, ng = -1;
while (ng + 1 < ok) {
int k = (ok + ng) / 2;
bool bl = check(prod(k, R));
if (bl) ok = k;
if (!bl) ng = k;
}
return ok;
}
};
#line 5 "string/suffix_array.hpp"
// 辞書順 i 番目の suffix が j 文字目始まりであるとき、
// SA[i] = j, ISA[j] = i
// |S|>0 を前提（そうでない場合 dummy 文字を追加して利用せよ）
struct Suffix_Array {
vc<int> SA;
vc<int> ISA;
vc<int> LCP;
Sparse_Table<Monoid_Min<int>> seg;
bool build_seg;
Suffix_Array(string& s) {
build_seg = 0;
assert(len(s) > 0);
char first = 127, last = 0;
for (auto&& c: s) {
chmin(first, c);
chmax(last, c);
}
SA = calc_suffix_array(s, first, last);
calc_LCP(s);
}
Suffix_Array(vc<int>& s) {
build_seg = 0;
assert(len(s) > 0);
SA = calc_suffix_array(s);
calc_LCP(s);
}
// lcp(S[i:], S[j:])
int lcp(int i, int j) {
if (!build_seg) {
build_seg = true;
seg.build(LCP);
}
int n = len(SA);
if (i == n || j == n) return 0;
if (i == j) return n - i;
i = ISA[i], j = ISA[j];
if (i > j) swap(i, j);
return seg.prod(i, j);
}
// S[i:] との lcp が n 以上であるような半開区間
pair<int, int> lcp_range(int i, int n) {
if (!build_seg) {
build_seg = true;
seg.build(LCP);
}
i = ISA[i];
int a = seg.min_left([&](auto e) -> bool { return e >= n; }, i);
int b = seg.max_right([&](auto e) -> bool { return e >= n; }, i);
return {a, b + 1};
}
// -1: S[L1:R1) < S[L2, R2)
// 0: S[L1:R1) = S[L2, R2)
// +1: S[L1:R1) > S[L2, R2)
int compare(int L1, int R1, int L2, int R2) {
int N = len(SA);
int n1 = R1 - L1, n2 = R2 - L2;
int n = lcp(L1, L2);
if (n == n1 && n == n2) return 0;
if (n == n1) return -1;
if (n == n2) return 1;
return (ISA[L1 + n] > ISA[L2 + n] ? 1 : -1);
}
private:
void induced_sort(const vc<int>& vect, int val_range, vc<int>& SA,
const vc<bool>& sl, const vc<int>& lms_idx) {
vc<int> l(val_range, 0), r(val_range, 0);
for (int c: vect) {
if (c + 1 < val_range) ++l[c + 1];
++r[c];
}
partial_sum(l.begin(), l.end(), l.begin());
partial_sum(r.begin(), r.end(), r.begin());
fill(SA.begin(), SA.end(), -1);
for (int i = (int)lms_idx.size() - 1; i >= 0; --i)
SA[--r[vect[lms_idx[i]]]] = lms_idx[i];
for (int i: SA)
if (i >= 1 && sl[i - 1]) SA[l[vect[i - 1]]++] = i - 1;
fill(r.begin(), r.end(), 0);
for (int c: vect) ++r[c];
partial_sum(r.begin(), r.end(), r.begin());
for (int k = (int)SA.size() - 1, i = SA[k]; k >= 1; --k, i = SA[k])
if (i >= 1 && !sl[i - 1]) { SA[--r[vect[i - 1]]] = i - 1; }
}
vc<int> SA_IS(const vc<int>& vect, int val_range) {
const int n = vect.size();
vc<int> SA(n), lms_idx;
vc<bool> sl(n);
sl[n - 1] = false;
for (int i = n - 2; i >= 0; --i) {
sl[i] = (vect[i] > vect[i + 1] || (vect[i] == vect[i + 1] && sl[i + 1]));
if (sl[i] && !sl[i + 1]) lms_idx.push_back(i + 1);
}
reverse(lms_idx.begin(), lms_idx.end());
induced_sort(vect, val_range, SA, sl, lms_idx);
vc<int> new_lms_idx(lms_idx.size()), lms_vec(lms_idx.size());
for (int i = 0, k = 0; i < n; ++i)
if (!sl[SA[i]] && SA[i] >= 1 && sl[SA[i] - 1]) {
new_lms_idx[k++] = SA[i];
}
int cur = 0;
SA[n - 1] = cur;
for (size_t k = 1; k < new_lms_idx.size(); ++k) {
int i = new_lms_idx[k - 1], j = new_lms_idx[k];
if (vect[i] != vect[j]) {
SA[j] = ++cur;
continue;
}
bool flag = false;
for (int a = i + 1, b = j + 1;; ++a, ++b) {
if (vect[a] != vect[b]) {
flag = true;
break;
}
if ((!sl[a] && sl[a - 1]) || (!sl[b] && sl[b - 1])) {
flag = !((!sl[a] && sl[a - 1]) && (!sl[b] && sl[b - 1]));
break;
}
}
SA[j] = (flag ? ++cur : cur);
}
for (size_t i = 0; i < lms_idx.size(); ++i) lms_vec[i] = SA[lms_idx[i]];
if (cur + 1 < (int)lms_idx.size()) {
auto lms_SA = SA_IS(lms_vec, cur + 1);
for (size_t i = 0; i < lms_idx.size(); ++i) {
new_lms_idx[i] = lms_idx[lms_SA[i]];
}
}
induced_sort(vect, val_range, SA, sl, new_lms_idx);
return SA;
}
vc<int> calc_suffix_array(const string& s, const char first = 'a',
const char last = 'z') {
vc<int> vect(s.size() + 1);
copy(begin(s), end(s), begin(vect));
for (auto& x: vect) x -= (int)first - 1;
vect.back() = 0;
auto ret = SA_IS(vect, (int)last - (int)first + 2);
ret.erase(ret.begin());
return ret;
}
vc<int> calc_suffix_array(const vc<int>& s) {
vc<int> ss = s;
UNIQUE(ss);
vc<int> vect(s.size() + 1);
copy(all(s), vect.begin());
for (auto& x: vect) x = LB(ss, x) + 1;
vect.back() = 0;
auto ret = SA_IS(vect, MAX(vect) + 2);
ret.erase(ret.begin());
return ret;
}
template <typename STRING>
void calc_LCP(const STRING& s) {
int n = s.size(), k = 0;
ISA.resize(n);
LCP.resize(n);
for (int i = 0; i < n; i++) ISA[SA[i]] = i;
for (int i = 0; i < n; i++, k ? k-- : 0) {
if (ISA[i] == n - 1) {
k = 0;
continue;
}
int j = SA[ISA[i] + 1];
while (i + k < n && j + k < n && s[i + k] == s[j + k]) k++;
LCP[ISA[i]] = k;
}
LCP.resize(n - 1);
}
};
#line 2 "string/sort_substrings.hpp"
// dp[i][j]：S[i:i+j) の rank
template <typename STRING>
vvc<int> sort_substrings(STRING& S, int max_len = -1) {
int n = len(S);
if (max_len == -1) max_len = n;
Suffix_Array sa(S);
auto& SA = sa.SA;
auto& LCP = sa.LCP;
int nxt = 0;
vv(int, dp, n, max_len + 1, -1);
FOR(i, len(SA)) {
auto L = SA[i];
FOR(k, 1, min(n - L, max_len) + 1) {
int R = L + k;
if (i > 0 && LCP[i - 1] >= k)
dp[L][R - L] = dp[SA[i - 1]][k];
else
dp[L][R - L] = nxt++;
}
}
return dp;
}
#line 2 "ds/segtree/segtree.hpp"
template <class Monoid>
struct SegTree {
using MX = Monoid;
using X = typename MX::value_type;
using value_type = X;
vc<X> dat;
int n, log, size;
SegTree() {}
SegTree(int n) { build(n); }
template <typename F>
SegTree(int n, F f) {
build(n, f);
}
SegTree(const vc<X>& v) { build(v); }
void build(int m) {
build(m, [](int i) -> X { return MX::unit(); });
}
void build(const vc<X>& v) {
build(len(v), [&](int i) -> X { return v[i]; });
}
template <typename F>
void build(int m, F f) {
n = m, log = 1;
while ((1 << log) < n) ++log;
size = 1 << log;
dat.assign(size << 1, MX::unit());
FOR(i, n) dat[size + i] = f(i);
FOR_R(i, 1, size) update(i);
}
X get(int i) { return dat[size + i]; }
vc<X> get_all() { return {dat.begin() + size, dat.begin() + size + n}; }
void update(int i) { dat[i] = Monoid::op(dat[2 * i], dat[2 * i + 1]); }
void set(int i, const X& x) {
assert(i < n);
dat[i += size] = x;
while (i >>= 1) update(i);
}
void multiply(int i, const X& x) {
assert(i < n);
i += size;
dat[i] = Monoid::op(dat[i], x);
while (i >>= 1) update(i);
}
X prod(int L, int R) {
assert(0 <= L && L <= R && R <= n);
X vl = Monoid::unit(), vr = Monoid::unit();
L += size, R += size;
while (L < R) {
if (L & 1) vl = Monoid::op(vl, dat[L++]);
if (R & 1) vr = Monoid::op(dat[--R], vr);
L >>= 1, R >>= 1;
}
return Monoid::op(vl, vr);
}
X prod_all() { return dat[1]; }
template <class F>
int max_right(F check, int L) {
assert(0 <= L && L <= n && check(Monoid::unit()));
if (L == n) return n;
L += size;
X sm = Monoid::unit();
do {
while (L % 2 == 0) L >>= 1;
if (!check(Monoid::op(sm, dat[L]))) {
while (L < size) {
L = 2 * L;
if (check(Monoid::op(sm, dat[L]))) { sm = Monoid::op(sm, dat[L++]); }
}
return L - size;
}
sm = Monoid::op(sm, dat[L++]);
} while ((L & -L) != L);
return n;
}
template <class F>
int min_left(F check, int R) {
assert(0 <= R && R <= n && check(Monoid::unit()));
if (R == 0) return 0;
R += size;
X sm = Monoid::unit();
do {
--R;
while (R > 1 && (R % 2)) R >>= 1;
if (!check(Monoid::op(dat[R], sm))) {
while (R < size) {
R = 2 * R + 1;
if (check(Monoid::op(dat[R], sm))) { sm = Monoid::op(dat[R--], sm); }
}
return R + 1 - size;
}
sm = Monoid::op(dat[R], sm);
} while ((R & -R) != R);
return 0;
}
// prod_{l<=i<r} A[i xor x]
X xor_prod(int l, int r, int xor_val) {
static_assert(Monoid::commute);
X x = Monoid::unit();
for (int k = 0; k < log + 1; ++k) {
if (l >= r) break;
if (l & 1) { x = Monoid::op(x, dat[(size >> k) + ((l++) ^ xor_val)]); }
if (r & 1) { x = Monoid::op(x, dat[(size >> k) + ((--r) ^ xor_val)]); }
l /= 2, r /= 2, xor_val /= 2;
}
return x;
}
};
#line 2 "alg/monoid/max.hpp"
template <typename E>
struct Monoid_Max {
using X = E;
using value_type = X;
static constexpr X op(const X &x, const X &y) noexcept { return max(x, y); }
static constexpr X unit() { return -infty<E>; }
static constexpr bool commute = true;
};
#line 7 "test_atcoder/abc240ex.test.cpp"
void solve() {
LL(N);
STR(S);
ll LIM = 1;
while (LIM * LIM < 2 * N) LIM++;
LIM += 10;
chmin(LIM, N);
auto rank = sort_substrings(S, LIM);
// 文字列ランク -> (L, R)
ll mx = 0;
FOR(i, len(rank)) chmax(mx, MAX(rank[i]));
vvc<pair<int, int>> LR(mx + 1);
FOR_R(i, N) FOR(j, LIM + 1) {
int r = rank[i][j];
if (r != -1) LR[r].eb(i, i + j);
}
using Mono = Monoid_Max<int>;
SegTree<Mono> seg(N + 1);
seg.set(0, 0);
vc<int> DP(N + 1, -infty<int>);
DP[0] = 0;
FOR(rk, mx + 1) {
for (auto&& [L, R]: LR[rk]) {
ll x = 1 + seg.prod(0, L + 1);
if (DP[R] < x) seg.set(R, x);
chmax(DP[R], x);
}
}
print(seg.prod_all());
}
signed main() {
solve();
return 0;
}