forked from Public-Mirror/Textractor
100 lines
4.5 KiB
C++
100 lines
4.5 KiB
C++
#include "extension.h"
|
|
|
|
std::vector<int> GenerateSuffixArray(const std::wstring& text)
|
|
{
|
|
std::vector<int> suffixArray(text.size());
|
|
for (int i = 0; i < text.size(); ++i) suffixArray[i] = i;
|
|
// The below code is a more efficient way of doing this:
|
|
// std::sort(suffixArray.begin(), suffixArray.end(), [&](int a, int b) { return wcscmp(text.c_str() + a, text.c_str() + b) > 0; });
|
|
std::stable_sort(suffixArray.begin(), suffixArray.end(), [&](int a, int b) { return text[a] > text[b]; });
|
|
std::vector<int> eqClasses(text.begin(), text.end());
|
|
std::vector<int> count(text.size());
|
|
for (int length = 1; length < text.size(); length *= 2)
|
|
{
|
|
// Determine equivalence class up to length, by checking length / 2 equivalence of suffixes and their following length / 2 suffixes
|
|
std::vector<int> prevEqClasses = eqClasses;
|
|
eqClasses[suffixArray[0]] = 0;
|
|
for (int i = 1; i < text.size(); ++i)
|
|
{
|
|
int currentSuffix = suffixArray[i];
|
|
int lastSuffix = suffixArray[i - 1];
|
|
if (currentSuffix + length < text.size() && prevEqClasses[currentSuffix] == prevEqClasses[lastSuffix] &&
|
|
prevEqClasses[currentSuffix + length / 2] == prevEqClasses.at(lastSuffix + length / 2)) // not completely certain that this will stay in range
|
|
eqClasses[currentSuffix] = eqClasses[lastSuffix];
|
|
else eqClasses[currentSuffix] = i;
|
|
}
|
|
|
|
// Sort within equivalence class based on order of following suffix after length (orders up to length * 2)
|
|
for (int i = 0; i < text.size(); ++i) count[i] = i;
|
|
for (auto suffix : std::vector(suffixArray))
|
|
{
|
|
int precedingSuffix = suffix - length;
|
|
if (precedingSuffix >= 0) suffixArray[count[eqClasses[precedingSuffix]]++] = precedingSuffix;
|
|
}
|
|
}
|
|
for (int i = 0; i + 1 < text.size(); ++i)
|
|
assert(wcscmp(text.c_str() + suffixArray[i], text.c_str() + suffixArray[i + 1]) > 0);
|
|
return suffixArray;
|
|
}
|
|
|
|
constexpr wchar_t ERASED = 0xf246; // inside Unicode private use area
|
|
|
|
bool ProcessSentence(std::wstring& sentence, SentenceInfo sentenceInfo)
|
|
{
|
|
if (sentenceInfo["text number"] == 0) return false;
|
|
|
|
// This algorithm looks for repeating substrings (in other words, common prefixes among the set of suffixes) of the sentence with length > 6
|
|
// It then looks for any regions of characters at least twice as long as the substring made up only of characters in the substring, and erases them
|
|
// If this results in the substring being completely erased from the string, the substring is copied to the last location where it was located in the original string
|
|
auto timeout = GetTickCount64() + 30'000; // give up if taking over 30 seconds
|
|
std::vector<int> suffixArray = GenerateSuffixArray(sentence);
|
|
for (int i = 0; i + 1 < sentence.size() && GetTickCount64() < timeout; ++i)
|
|
{
|
|
int commonPrefixLength = 0;
|
|
for (int j = suffixArray[i], k = suffixArray[i + 1]; j < sentence.size() && k < sentence.size(); ++j, ++k)
|
|
if (sentence[j] != ERASED && sentence[j] == sentence[k]) commonPrefixLength += 1;
|
|
else break;
|
|
|
|
if (commonPrefixLength > 6)
|
|
{
|
|
std::wstring substring(sentence, suffixArray[i], commonPrefixLength);
|
|
bool substringCharMap[0x10000] = {};
|
|
for (auto ch : substring)
|
|
substringCharMap[ch] = true;
|
|
|
|
for (int regionSize = 0, j = 0; j <= sentence.size(); ++j)
|
|
if (substringCharMap[sentence[j]]) regionSize += 1;
|
|
else if (regionSize >= commonPrefixLength * 2)
|
|
while (regionSize > 0)
|
|
sentence[j - regionSize--] = ERASED;
|
|
else regionSize = 0;
|
|
|
|
if (!wcsstr(sentence.c_str(), substring.c_str())) std::copy(substring.begin(), substring.end(), sentence.begin() + max(suffixArray[i], suffixArray[i + 1]));
|
|
}
|
|
}
|
|
sentence.erase(std::remove(sentence.begin(), sentence.end(), ERASED), sentence.end());
|
|
return true;
|
|
}
|
|
|
|
TEST(
|
|
{
|
|
InfoForExtension nonConsole[] = { { "text number", 1 }, {} };
|
|
|
|
std::wstring cyclicRepeats = L"Name: '_abcdefg_abcdefg_abcdefg_abcdefg_abcdefg'";
|
|
std::wstring buildupRepeats = L"Name: '__a_ab_abc_abcd_abcde_abcdef_abcdefg'";
|
|
std::wstring breakdownRepeats = L"Name: '_abcdefg_abcdef_abcde_abcd_abc_ab_a_'";
|
|
ProcessSentence(cyclicRepeats, { nonConsole });
|
|
ProcessSentence(buildupRepeats, { nonConsole });
|
|
ProcessSentence(breakdownRepeats, { nonConsole });
|
|
assert(cyclicRepeats == L"Name: '_abcdefg'");
|
|
assert(buildupRepeats == L"Name: '_abcdefg'");
|
|
assert(breakdownRepeats == L"Name: '_abcdefg'");
|
|
|
|
std::wstring empty = L"", one = L" ", normal = L"This is a normal sentence. はい";
|
|
ProcessSentence(empty, { nonConsole });
|
|
ProcessSentence(one, { nonConsole });
|
|
ProcessSentence(normal, { nonConsole });
|
|
assert(empty == L"" && one == L" " && normal == L"This is a normal sentence. はい");
|
|
}
|
|
);
|