#define PROBLEM "https://judge.yosupo.jp/problem/longest_common_substring"
#include "../../string/longest_common_substring.hpp"
#include <algorithm>
#include <cassert>
#include <cstdint>
#include "../../utilities/fast_io.hpp"
#include <string>
#include <vector>
namespace {
template <class Sequence>
bool equal_substring(
const Sequence& first,
int first_left,
const Sequence& second,
int second_left,
int length
) {
for (int i = 0; i < length; i++) {
if (first[first_left + i] != second[second_left + i]) return false;
}
return true;
}
template <class Sequence>
int naive_length(const Sequence& first, const Sequence& second) {
int n = int(first.size());
int m = int(second.size());
int result = 0;
for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) {
int length = 0;
while (
i + length < n &&
j + length < m &&
first[i + length] == second[j + length]
) {
length++;
}
result = std::max(result, length);
}
}
return result;
}
template <class Sequence>
void check_result(const Sequence& first, const Sequence& second) {
auto result = m1une::string::longest_common_substring(first, second);
int n = int(first.size());
int m = int(second.size());
int length = result.length();
assert(0 <= result.first_left && result.first_left <= result.first_right && result.first_right <= n);
assert(0 <= result.second_left && result.second_left <= result.second_right && result.second_right <= m);
assert(result.second_right - result.second_left == length);
assert(equal_substring(first, result.first_left, second, result.second_left, length));
assert(length == naive_length(first, second));
if (length == 0) {
assert(result.first_left == 0);
assert(result.first_right == 0);
assert(result.second_left == 0);
assert(result.second_right == 0);
assert(result.empty());
}
}
void test_fixed() {
check_result(std::string(), std::string());
check_result(std::string("abc"), std::string());
check_result(std::string(), std::string("abc"));
check_result(std::string("abc"), std::string("def"));
check_result(std::string("xabxac"), std::string("abcabxabcd"));
check_result(std::string("banana"), std::string("ananas"));
auto result = m1une::string::longest_common_substring(
std::string("xabxac"),
std::string("abcabxabcd")
);
assert(result.length() == 4);
assert((result.first_interval() == std::make_pair(result.first_left, result.first_right)));
assert((result.second_interval() == std::make_pair(result.second_left, result.second_right)));
std::vector<int> first;
first.push_back(3);
first.push_back(-1);
first.push_back(4);
first.push_back(-1);
first.push_back(5);
std::vector<int> second;
second.push_back(9);
second.push_back(4);
second.push_back(-1);
second.push_back(5);
second.push_back(9);
check_result(first, second);
auto vector_result = m1une::string::longest_common_substring(first, second);
assert(vector_result.length() == 3);
}
void test_randomized() {
std::uint64_t state = 20260709;
auto random = [&state]() {
state ^= state << 7;
state ^= state >> 9;
return state;
};
for (int trial = 0; trial < 2000; trial++) {
int n = int(random() % 35);
int m = int(random() % 35);
std::string first(n, 'a');
std::string second(m, 'a');
for (char& character : first) character = char('a' + random() % 5);
for (char& character : second) character = char('a' + random() % 5);
check_result(first, second);
std::vector<int> first_values(n);
std::vector<int> second_values(m);
for (int& value : first_values) value = int(random() % 7) - 3;
for (int& value : second_values) value = int(random() % 7) - 3;
check_result(first_values, second_values);
}
}
} // namespace
int main() {
m1une::utilities::FastInput fast_input;
m1une::utilities::FastOutput fast_output;
test_fixed();
test_randomized();
std::string first, second;
fast_input >> first >> second;
auto result = m1une::string::longest_common_substring(first, second);
fast_output << result.first_left << ' ' << result.first_right << ' '
<< result.second_left << ' ' << result.second_right << '\n';
}
#line 1 "verify/string/longest_common_substring.test.cpp"
#define PROBLEM "https://judge.yosupo.jp/problem/longest_common_substring"
#line 1 "string/longest_common_substring.hpp"
#include <algorithm>
#include <cassert>
#include <type_traits>
#include <utility>
#include <vector>
#line 1 "string/suffix_array.hpp"
#line 6 "string/suffix_array.hpp"
#include <numeric>
#include <string>
#line 10 "string/suffix_array.hpp"
namespace m1une {
namespace string {
namespace detail {
template <class Sequence>
std::vector<int> suffix_array_impl(const Sequence& sequence) {
int n = int(sequence.size());
if (n == 0) return {};
using Value = std::remove_cv_t<std::remove_reference_t<decltype(sequence[0])>>;
std::vector<Value> sorted(sequence.begin(), sequence.end());
std::sort(sorted.begin(), sorted.end());
sorted.erase(std::unique(sorted.begin(), sorted.end()), sorted.end());
int length = n + 1;
std::vector<int> order(length);
std::vector<int> rank(length);
std::vector<int> key(length);
key[n] = 0;
for (int i = 0; i < n; i++) {
key[i] = int(std::lower_bound(sorted.begin(), sorted.end(), sequence[i]) - sorted.begin()) + 1;
}
int alphabet = int(sorted.size()) + 1;
std::vector<int> count(std::max(length, alphabet), 0);
for (int value : key) count[value]++;
for (int i = 1; i < alphabet; i++) count[i] += count[i - 1];
for (int i = length - 1; i >= 0; i--) order[--count[key[i]]] = i;
int classes = 1;
rank[order[0]] = 0;
for (int i = 1; i < length; i++) {
if (key[order[i - 1]] != key[order[i]]) classes++;
rank[order[i]] = classes - 1;
}
std::vector<int> shifted(length);
std::vector<int> next_rank(length);
for (long long half = 1; half < length; half <<= 1) {
for (int i = 0; i < length; i++) {
long long position = order[i] - half;
if (position < 0) position += length;
shifted[i] = int(position);
}
count.assign(classes, 0);
for (int position : shifted) count[rank[position]]++;
for (int i = 1; i < classes; i++) count[i] += count[i - 1];
for (int i = length - 1; i >= 0; i--) {
int position = shifted[i];
order[--count[rank[position]]] = position;
}
int next_classes = 1;
next_rank[order[0]] = 0;
for (int i = 1; i < length; i++) {
int current = order[i];
int previous = order[i - 1];
int current_second = int((current + half) % length);
int previous_second = int((previous + half) % length);
if (
rank[current] != rank[previous] ||
rank[current_second] != rank[previous_second]
) {
next_classes++;
}
next_rank[current] = next_classes - 1;
}
rank.swap(next_rank);
classes = next_classes;
if (classes == length) break;
}
std::vector<int> suffixes(n);
for (int i = 0; i < n; i++) suffixes[i] = order[i + 1];
return suffixes;
}
} // namespace detail
template <class Sequence>
std::vector<int> suffix_array(const Sequence& sequence) {
return detail::suffix_array_impl(sequence);
}
inline std::vector<int> suffix_array(const std::string& text) {
std::vector<unsigned char> values;
values.reserve(text.size());
for (unsigned char character : text) values.push_back(character);
return detail::suffix_array_impl(values);
}
template <class Sequence>
std::vector<int> lcp_array(const Sequence& sequence, const std::vector<int>& suffixes) {
int n = int(sequence.size());
assert(int(suffixes.size()) == n);
if (n == 0) return {};
std::vector<int> rank(n);
for (int i = 0; i < n; i++) {
assert(0 <= suffixes[i] && suffixes[i] < n);
rank[suffixes[i]] = i;
}
std::vector<int> lcp(n - 1);
int common = 0;
for (int i = 0; i < n; i++) {
int position = rank[i];
if (position == n - 1) {
common = 0;
continue;
}
int j = suffixes[position + 1];
while (
i + common < n &&
j + common < n &&
sequence[i + common] == sequence[j + common]
) {
common++;
}
lcp[position] = common;
if (common > 0) common--;
}
return lcp;
}
} // namespace string
} // namespace m1une
#line 11 "string/longest_common_substring.hpp"
namespace m1une {
namespace string {
struct LongestCommonSubstring {
int first_left = 0;
int first_right = 0;
int second_left = 0;
int second_right = 0;
int length() const {
assert(first_right - first_left == second_right - second_left);
return first_right - first_left;
}
bool empty() const {
return length() == 0;
}
std::pair<int, int> first_interval() const {
return {first_left, first_right};
}
std::pair<int, int> second_interval() const {
return {second_left, second_right};
}
};
namespace detail {
template <class Sequence>
std::vector<int> compressed_join_with_separator(const Sequence& first, const Sequence& second) {
using Value = std::remove_cv_t<std::remove_reference_t<decltype(first[0])>>;
std::vector<Value> values;
values.reserve(first.size() + second.size());
for (const auto& value : first) values.push_back(value);
for (const auto& value : second) values.push_back(value);
std::sort(values.begin(), values.end());
values.erase(std::unique(values.begin(), values.end()), values.end());
std::vector<int> joined;
joined.reserve(first.size() + second.size() + 1);
for (const auto& value : first) {
joined.push_back(int(std::lower_bound(values.begin(), values.end(), value) - values.begin()) + 2);
}
joined.push_back(1);
for (const auto& value : second) {
joined.push_back(int(std::lower_bound(values.begin(), values.end(), value) - values.begin()) + 2);
}
return joined;
}
} // namespace detail
template <class Sequence>
LongestCommonSubstring longest_common_substring(const Sequence& first, const Sequence& second) {
int n = int(first.size());
int m = int(second.size());
std::vector<int> joined = detail::compressed_join_with_separator(first, second);
std::vector<int> suffixes = suffix_array(joined);
std::vector<int> lcp = lcp_array(joined, suffixes);
LongestCommonSubstring result;
for (int i = 0; i + 1 < int(suffixes.size()); i++) {
int a = suffixes[i];
int b = suffixes[i + 1];
if (a == n || b == n) continue;
bool a_first = a < n;
bool b_first = b < n;
if (a_first == b_first) continue;
int first_left = a_first ? a : b;
int second_left = a_first ? b - n - 1 : a - n - 1;
int length = lcp[i];
length = std::min(length, n - first_left);
length = std::min(length, m - second_left);
if (length > result.length()) {
result.first_left = first_left;
result.first_right = first_left + length;
result.second_left = second_left;
result.second_right = second_left + length;
}
}
return result;
}
} // namespace string
} // namespace m1une
#line 4 "verify/string/longest_common_substring.test.cpp"
#line 7 "verify/string/longest_common_substring.test.cpp"
#include <cstdint>
#line 1 "utilities/fast_io.hpp"
#line 5 "utilities/fast_io.hpp"
#include <array>
#include <cerrno>
#include <charconv>
#include <cstddef>
#include <cstdio>
#include <cstdlib>
#line 12 "utilities/fast_io.hpp"
#include <cstring>
#include <iterator>
#line 15 "utilities/fast_io.hpp"
#include <sys/stat.h>
#line 18 "utilities/fast_io.hpp"
#include <unistd.h>
#line 20 "utilities/fast_io.hpp"
namespace m1une {
namespace utilities {
struct FastOutput;
namespace internal {
// Shared with the convenience helpers in template.hpp.
inline FastOutput* standard_output_instance = nullptr;
// Detect std::begin(x), std::end(x).
template <class T, class = void>
struct is_range : std::false_type {};
template <class T>
struct is_range<T, std::void_t<
decltype(std::begin(std::declval<T&>())),
decltype(std::end(std::declval<T&>()))
>> : std::true_type {};
template <class T>
inline constexpr bool is_range_v = is_range<T>::value;
template <class T>
using range_reference_t = decltype(*std::begin(std::declval<T&>()));
template <class T>
using range_value_t = std::remove_cv_t<std::remove_reference_t<range_reference_t<T>>>;
template <class T, class = void>
struct range_stored_value {
using type = range_value_t<T>;
};
template <class T>
struct range_stored_value<T, std::void_t<typename std::remove_cv_t<std::remove_reference_t<T>>::value_type>> {
using type = typename std::remove_cv_t<std::remove_reference_t<T>>::value_type;
};
template <class T>
using range_stored_value_t = typename range_stored_value<T>::type;
// Treat strings and C strings as scalar output objects, not as ranges.
template <class T>
struct is_char_array : std::false_type {};
template <class T, std::size_t N>
struct is_char_array<T[N]>
: std::bool_constant<std::is_same_v<std::remove_cv_t<T>, char>> {};
template <class T>
struct is_string_like
: std::bool_constant<
std::is_same_v<std::decay_t<T>, std::string>
|| std::is_same_v<std::decay_t<T>, const char*>
|| std::is_same_v<std::decay_t<T>, char*>
|| is_char_array<std::remove_reference_t<T>>::value
> {};
template <class T>
inline constexpr bool is_string_like_v = is_string_like<T>::value;
// ModInt-like type: x.val() is printable, and x can be assigned from long long.
template <class T, class = void>
struct has_val_method : std::false_type {};
template <class T>
struct has_val_method<T, std::void_t<decltype(std::declval<const T&>().val())>>
: std::true_type {};
template <class T>
inline constexpr bool has_val_method_v = has_val_method<T>::value;
template <class T, class = void>
struct has_static_mod_raw : std::false_type {};
template <class T>
struct has_static_mod_raw<
T, std::void_t<decltype(T::mod()), decltype(T::raw(std::declval<uint32_t>()))>>
: std::true_type {};
template <class T>
inline constexpr bool has_static_mod_raw_v = has_static_mod_raw<T>::value;
// libstdc++ before GCC 16 does not classify __int128 as an integral type in
// strict ISO modes such as -std=c++23. Keep the fast-I/O interface independent
// of that implementation detail.
template <class T>
inline constexpr bool is_integral_v =
std::is_integral_v<T>
|| std::is_same_v<std::remove_cv_t<T>, __int128_t>
|| std::is_same_v<std::remove_cv_t<T>, __uint128_t>;
template <class T>
inline constexpr bool is_signed_v =
std::is_signed_v<T>
|| std::is_same_v<std::remove_cv_t<T>, __int128_t>;
template <class T>
struct make_unsigned {
using type = std::make_unsigned_t<T>;
};
template <>
struct make_unsigned<__int128_t> {
using type = __uint128_t;
};
template <>
struct make_unsigned<__uint128_t> {
using type = __uint128_t;
};
template <class T>
using make_unsigned_t = typename make_unsigned<std::remove_cv_t<T>>::type;
} // namespace internal
struct FastInput {
static constexpr int buffer_size = 1 << 20;
private:
std::FILE* _stream;
char _buffer[buffer_size];
int _position;
int _length;
int _file_descriptor;
bool _streaming;
bool refill() {
_position = 0;
if (_streaming) {
ssize_t length;
do {
length = ::read(_file_descriptor, _buffer, buffer_size);
} while (length < 0 && errno == EINTR);
if (length <= 0) {
_length = 0;
return false;
}
_length = int(length);
} else {
_length = int(std::fread(_buffer, 1, buffer_size, _stream));
}
return _length != 0;
}
template <class T>
bool read_integer_from_stream(T& value) {
if (!skip_spaces()) return false;
int c = read_char_raw();
bool negative = false;
if (c == '-') {
negative = true;
c = read_char_raw();
}
if constexpr (internal::is_signed_v<T>) {
T result = 0;
while ('0' <= c && c <= '9') {
result = negative ? result * 10 - (c - '0')
: result * 10 + (c - '0');
c = read_char_raw();
}
value = result;
} else {
T result = 0;
while ('0' <= c && c <= '9') {
result = result * 10 + T(c - '0');
c = read_char_raw();
}
value = negative ? T(0) - result : result;
}
return true;
}
bool prepare_number() {
if (_length - _position >= 64) return true;
const int remaining = _length - _position;
if (remaining > 0) std::memmove(_buffer, _buffer + _position, remaining);
const int added = int(std::fread(_buffer + remaining, 1, buffer_size - remaining, _stream));
_position = 0;
_length = remaining + added;
if (_length < buffer_size) _buffer[_length] = '\0';
return _length != 0;
}
public:
explicit FastInput(std::FILE* stream = stdin)
: _stream(stream),
_position(0),
_length(0),
_file_descriptor(::fileno(stream)),
_streaming([&] {
struct stat status;
return _file_descriptor >= 0
&& ::fstat(_file_descriptor, &status) == 0
&& !S_ISREG(status.st_mode);
}()) {}
FastInput(const FastInput&) = delete;
FastInput& operator=(const FastInput&) = delete;
int read_char_raw() {
if (_position == _length && !refill()) return EOF;
return _buffer[_position++];
}
bool skip_spaces() {
int c = read_char_raw();
while (c != EOF && c <= ' ') c = read_char_raw();
if (c == EOF) return false;
--_position;
return true;
}
bool read(char& value) {
if (!skip_spaces()) return false;
value = char(read_char_raw());
return true;
}
bool read(std::string& value) {
if (!skip_spaces()) return false;
value.clear();
while (true) {
const int begin = _position;
while (_position < _length &&
static_cast<unsigned char>(_buffer[_position]) > ' ') {
++_position;
}
value.append(_buffer + begin, _position - begin);
if (_position < _length) {
++_position;
return true;
}
if (!refill()) return true;
}
}
bool read(bool& value) {
int x;
if (!read(x)) return false;
value = x != 0;
return true;
}
template <class T>
std::enable_if_t<
internal::is_integral_v<T>
&& !std::is_same_v<std::remove_cv_t<T>, bool>
&& !std::is_same_v<std::remove_cv_t<T>, char>,
bool
>
read(T& value) {
if (_streaming) return read_integer_from_stream(value);
if (!prepare_number()) return false;
int c = static_cast<unsigned char>(_buffer[_position++]);
while (c <= ' ') c = static_cast<unsigned char>(_buffer[_position++]);
bool negative = false;
if (c == '-') {
negative = true;
c = static_cast<unsigned char>(_buffer[_position++]);
}
if constexpr (internal::is_signed_v<T>) {
T result = 0;
while ('0' <= c && c <= '9') {
const int first = c - '0';
const int second = static_cast<unsigned char>(_buffer[_position]) - '0';
if (0 <= second && second <= 9) {
result = negative ? result * 100 - (first * 10 + second)
: result * 100 + (first * 10 + second);
++_position;
} else {
result = negative ? result * 10 - first : result * 10 + first;
}
c = static_cast<unsigned char>(_buffer[_position++]);
}
value = result;
} else {
T result = 0;
while ('0' <= c && c <= '9') {
const unsigned first = unsigned(c - '0');
const int second = static_cast<unsigned char>(_buffer[_position]) - '0';
if (0 <= second && second <= 9) {
result = result * 100 + T(first * 10 + unsigned(second));
++_position;
} else {
result = result * 10 + T(first);
}
c = static_cast<unsigned char>(_buffer[_position++]);
}
value = negative ? T(0) - result : result;
}
if (_position > _length) _position = _length;
return true;
}
template <class T>
std::enable_if_t<std::is_floating_point_v<T>, bool>
read(T& value) {
if (!skip_spaces()) return false;
int c = read_char_raw();
bool negative = false;
if (c == '-' || c == '+') {
negative = c == '-';
c = read_char_raw();
}
long double result = 0;
while ('0' <= c && c <= '9') {
result = result * 10 + (c - '0');
c = read_char_raw();
}
if (c == '.') {
long double place = 0.1L;
c = read_char_raw();
while ('0' <= c && c <= '9') {
result += (c - '0') * place;
place *= 0.1L;
c = read_char_raw();
}
}
if (c == 'e' || c == 'E') {
c = read_char_raw();
bool exponent_negative = false;
if (c == '-' || c == '+') {
exponent_negative = c == '-';
c = read_char_raw();
}
int exponent = 0;
while ('0' <= c && c <= '9') {
exponent = exponent * 10 + (c - '0');
c = read_char_raw();
}
long double scale = 1;
long double power = 10;
while (exponent > 0) {
if (exponent & 1) scale *= power;
power *= power;
exponent >>= 1;
}
result = exponent_negative ? result / scale : result * scale;
}
value = static_cast<T>(negative ? -result : result);
return true;
}
template <class T>
std::enable_if_t<
internal::has_val_method_v<T>
&& !internal::is_integral_v<T>
&& !internal::is_range_v<T>,
bool
>
read(T& value) {
long long x;
if (!read(x)) return false;
if constexpr (internal::has_static_mod_raw_v<T>) {
if (x >= 0 && uint64_t(x) < uint64_t(T::mod())) {
value = T::raw(uint32_t(x));
} else {
value = T(x);
}
} else {
value = T(x);
}
return true;
}
template <class First, class Second>
bool read(std::pair<First, Second>& value) {
if (!read(value.first)) return false;
return read(value.second);
}
template <class Range>
std::enable_if_t<
internal::is_range_v<Range>
&& !internal::is_string_like_v<Range>,
bool
>
read(Range& range) {
using StoredValue = internal::range_stored_value_t<Range>;
constexpr bool nested = internal::is_range_v<StoredValue>
&& !internal::is_string_like_v<StoredValue>;
for (auto&& value : range) {
if constexpr (std::is_same_v<StoredValue, bool> && !nested) {
bool x;
if (!read(x)) return false;
value = x;
} else {
if (!read(value)) return false;
}
}
return true;
}
template <class First, class Second, class... Rest>
bool read(First& first, Second& second, Rest&... rest) {
if (!read(first)) return false;
return read(second, rest...);
}
template <class T>
FastInput& operator>>(T& value) {
if (!read(value)) std::abort();
return *this;
}
};
struct FastOutput {
static constexpr int buffer_size = 1 << 20;
private:
inline static const auto digit_quads = [] {
std::array<char, 40000> result{};
for (int i = 0; i < 10000; i++) {
int value = i;
for (int j = 3; j >= 0; j--) {
result[4 * i + j] = char('0' + value % 10);
value /= 10;
}
}
return result;
}();
std::FILE* _stream;
char _buffer[buffer_size];
int _position;
int _precision;
std::chars_format _float_format;
char _range_separator;
std::string* _capture = nullptr;
template <class T>
std::string format_cell(const T& value) {
std::string result;
struct CaptureGuard {
std::string*& target;
std::string* previous;
~CaptureGuard() { target = previous; }
} guard{_capture, _capture};
_capture = &result;
write(value);
return result;
}
template <class Matrix>
void write_aligned_matrix(const Matrix& matrix) {
std::vector<std::vector<std::string>> rows;
std::vector<std::size_t> widths;
for (const auto& row : matrix) {
auto& cells = rows.emplace_back();
std::size_t column = 0;
for (const auto& value : row) {
cells.push_back(format_cell(value));
if (column == widths.size()) widths.push_back(0);
widths[column] = std::max(widths[column], cells.back().size());
++column;
}
}
bool first = true;
for (const auto& row : rows) {
if (!first) write_char('\n');
first = false;
for (std::size_t column = 0; column < row.size(); ++column) {
if (column != 0) write_char(_range_separator);
for (std::size_t padding = row[column].size();
padding < widths[column]; ++padding) {
write_char(' ');
}
write(row[column]);
}
}
}
public:
explicit FastOutput(std::FILE* stream = stdout)
: _stream(stream),
_position(0),
_precision(6),
_float_format(std::chars_format::general),
_range_separator(' ') {
if (_stream == stdout
&& internal::standard_output_instance == nullptr) {
internal::standard_output_instance = this;
}
}
FastOutput(const FastOutput&) = delete;
FastOutput& operator=(const FastOutput&) = delete;
~FastOutput() {
flush();
if (internal::standard_output_instance == this) {
internal::standard_output_instance = nullptr;
}
}
void flush() {
if (_position != 0) {
std::fwrite(_buffer, 1, _position, _stream);
_position = 0;
}
std::fflush(_stream);
}
void write_char(char c) {
if (_capture != nullptr) {
_capture->push_back(c);
return;
}
if (_position == buffer_size) flush();
_buffer[_position++] = c;
}
void write(const char* s) {
while (*s != '\0') write_char(*s++);
}
void write(const std::string& s) {
if (_capture != nullptr) {
_capture->append(s);
return;
}
std::size_t position = 0;
while (position < s.size()) {
if (_position == buffer_size) flush();
const std::size_t copied =
std::min<std::size_t>(buffer_size - _position, s.size() - position);
std::memcpy(_buffer + _position, s.data() + position, copied);
_position += int(copied);
position += copied;
}
}
void write(char c) {
write_char(c);
}
void write(bool value) {
write_char(value ? '1' : '0');
}
template <class T>
std::enable_if_t<std::is_floating_point_v<T>>
write(T value) {
char digits[128];
auto [end, error] = std::to_chars(
digits,
digits + sizeof(digits),
value,
_float_format,
_precision
);
if (error != std::errc()) std::abort();
for (const char* pointer = digits; pointer != end; pointer++) {
write_char(*pointer);
}
}
template <class T>
std::enable_if_t<
internal::is_integral_v<T>
&& !std::is_same_v<std::remove_cv_t<T>, bool>
&& !std::is_same_v<std::remove_cv_t<T>, char>
>
write(T value) {
using Raw = std::remove_cv_t<T>;
using Unsigned = internal::make_unsigned_t<Raw>;
Unsigned magnitude;
if constexpr (internal::is_signed_v<Raw>) {
if (value < 0) {
write_char('-');
magnitude = Unsigned(0) - Unsigned(value);
} else {
magnitude = Unsigned(value);
}
} else {
magnitude = value;
}
if (magnitude == 0) {
write_char('0');
return;
}
unsigned chunks[16];
int count = 0;
while (magnitude >= 10000) {
const Unsigned quotient = magnitude / 10000;
chunks[count++] = unsigned(magnitude - quotient * 10000);
magnitude = quotient;
}
if (_capture == nullptr && _position > buffer_size - 64) flush();
char captured[64];
char* const begin = _capture != nullptr ? captured : _buffer + _position;
char* destination = begin;
const unsigned leading = unsigned(magnitude);
const char* first = digit_quads.data() + 4 * leading;
int skip = leading < 10 ? 3 : leading < 100 ? 2 : leading < 1000 ? 1 : 0;
for (; skip < 4; skip++) *destination++ = first[skip];
while (count--) {
const char* digits = digit_quads.data() + 4 * chunks[count];
std::memcpy(destination, digits, 4);
destination += 4;
}
if (_capture != nullptr) {
_capture->append(begin, destination - begin);
} else {
_position += int(destination - begin);
}
}
template <class T>
std::enable_if_t<
internal::has_val_method_v<T>
&& !internal::is_integral_v<T>
&& !internal::is_range_v<T>
>
write(const T& value) {
write(value.val());
}
template <class First, class Second>
void write(const std::pair<First, Second>& value) {
write(value.first);
write_char(' ');
write(value.second);
}
template <class Range>
std::enable_if_t<
internal::is_range_v<Range>
&& !internal::is_string_like_v<Range>
>
write(const Range& range) {
using StoredValue = internal::range_stored_value_t<const Range>;
constexpr bool nested = internal::is_range_v<StoredValue>
&& !internal::is_string_like_v<StoredValue>;
bool first = true;
for (const auto& value : range) {
if (!first) write_char(nested ? '\n' : _range_separator);
first = false;
if constexpr (std::is_same_v<StoredValue, bool> && !nested) {
write(static_cast<bool>(value));
} else {
write(value);
}
}
}
template <class First, class... Rest>
void print(const First& first, const Rest&... rest) {
write(first);
((write_char(' '), write(rest)), ...);
}
void println() {
write_char('\n');
}
void set_precision(int precision) {
_precision = precision;
}
void set_fixed(int precision = 6) {
_float_format = std::chars_format::fixed;
_precision = precision;
}
void set_general(int precision = 6) {
_float_format = std::chars_format::general;
_precision = precision;
}
void set_range_separator(char separator) {
_range_separator = separator;
}
template <class Matrix>
void write_aligned(const Matrix& matrix) {
using Row = internal::range_stored_value_t<const Matrix>;
using Cell = internal::range_stored_value_t<const Row>;
static_assert(internal::is_range_v<Row> && !internal::is_string_like_v<Row>,
"write_aligned requires a two-dimensional range");
static_assert(!internal::is_range_v<Cell> || internal::is_string_like_v<Cell>,
"write_aligned requires scalar cells");
write_aligned_matrix(matrix);
}
template <class Matrix>
void println_aligned(const Matrix& matrix) {
write_aligned(matrix);
write_char('\n');
}
template <class... Args>
void println(const Args&... args) {
print(args...);
write_char('\n');
}
template <class T>
FastOutput& operator<<(const T& value) {
write(value);
return *this;
}
};
} // namespace utilities
} // namespace m1une
#line 11 "verify/string/longest_common_substring.test.cpp"
namespace {
template <class Sequence>
bool equal_substring(
const Sequence& first,
int first_left,
const Sequence& second,
int second_left,
int length
) {
for (int i = 0; i < length; i++) {
if (first[first_left + i] != second[second_left + i]) return false;
}
return true;
}
template <class Sequence>
int naive_length(const Sequence& first, const Sequence& second) {
int n = int(first.size());
int m = int(second.size());
int result = 0;
for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) {
int length = 0;
while (
i + length < n &&
j + length < m &&
first[i + length] == second[j + length]
) {
length++;
}
result = std::max(result, length);
}
}
return result;
}
template <class Sequence>
void check_result(const Sequence& first, const Sequence& second) {
auto result = m1une::string::longest_common_substring(first, second);
int n = int(first.size());
int m = int(second.size());
int length = result.length();
assert(0 <= result.first_left && result.first_left <= result.first_right && result.first_right <= n);
assert(0 <= result.second_left && result.second_left <= result.second_right && result.second_right <= m);
assert(result.second_right - result.second_left == length);
assert(equal_substring(first, result.first_left, second, result.second_left, length));
assert(length == naive_length(first, second));
if (length == 0) {
assert(result.first_left == 0);
assert(result.first_right == 0);
assert(result.second_left == 0);
assert(result.second_right == 0);
assert(result.empty());
}
}
void test_fixed() {
check_result(std::string(), std::string());
check_result(std::string("abc"), std::string());
check_result(std::string(), std::string("abc"));
check_result(std::string("abc"), std::string("def"));
check_result(std::string("xabxac"), std::string("abcabxabcd"));
check_result(std::string("banana"), std::string("ananas"));
auto result = m1une::string::longest_common_substring(
std::string("xabxac"),
std::string("abcabxabcd")
);
assert(result.length() == 4);
assert((result.first_interval() == std::make_pair(result.first_left, result.first_right)));
assert((result.second_interval() == std::make_pair(result.second_left, result.second_right)));
std::vector<int> first;
first.push_back(3);
first.push_back(-1);
first.push_back(4);
first.push_back(-1);
first.push_back(5);
std::vector<int> second;
second.push_back(9);
second.push_back(4);
second.push_back(-1);
second.push_back(5);
second.push_back(9);
check_result(first, second);
auto vector_result = m1une::string::longest_common_substring(first, second);
assert(vector_result.length() == 3);
}
void test_randomized() {
std::uint64_t state = 20260709;
auto random = [&state]() {
state ^= state << 7;
state ^= state >> 9;
return state;
};
for (int trial = 0; trial < 2000; trial++) {
int n = int(random() % 35);
int m = int(random() % 35);
std::string first(n, 'a');
std::string second(m, 'a');
for (char& character : first) character = char('a' + random() % 5);
for (char& character : second) character = char('a' + random() % 5);
check_result(first, second);
std::vector<int> first_values(n);
std::vector<int> second_values(m);
for (int& value : first_values) value = int(random() % 7) - 3;
for (int& value : second_values) value = int(random() % 7) - 3;
check_result(first_values, second_values);
}
}
} // namespace
int main() {
m1une::utilities::FastInput fast_input;
m1une::utilities::FastOutput fast_output;
test_fixed();
test_randomized();
std::string first, second;
fast_input >> first >> second;
auto result = m1une::string::longest_common_substring(first, second);
fast_output << result.first_left << ' ' << result.first_right << ' '
<< result.second_left << ' ' << result.second_right << '\n';
}
verify/string/longest_common_substring.test.cpp