Paginator

oster_man

Jun 3rd, 2023

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#include <algorithm>
#include <cmath>
#include <iostream>
#include <map>
#include <set>
#include <stdexcept>
#include <string>
#include <utility>
#include <vector>
using namespace std;
const int MAX_RESULT_DOCUMENT_COUNT = 5;
string ReadLine() {
string s;
getline(cin, s);
return s;
}
int ReadLineWithNumber() {
int result;
cin >> result;
ReadLine();
return result;
}
vector<string> SplitIntoWords(const string& text) {
vector<string> words;
string word;
for (const char c : text) {
if (c == ' ') {
if (!word.empty()) {
words.push_back(word);
word.clear();
}
} else {
word += c;
}
}
if (!word.empty()) {
words.push_back(word);
}
return words;
}
struct Document {
Document() = default;
Document(int id, double relevance, int rating)
: id(id)
, relevance(relevance)
, rating(rating) {
}
int id = 0;
double relevance = 0.0;
int rating = 0;
};
template <typename StringContainer>
set<string> MakeUniqueNonEmptyStrings(const StringContainer& strings) {
set<string> non_empty_strings;
for (const string& str : strings) {
if (!str.empty()) {
non_empty_strings.insert(str);
}
}
return non_empty_strings;
}
enum class DocumentStatus {
ACTUAL,
IRRELEVANT,
BANNED,
REMOVED,
};
class SearchServer {
public:
template <typename StringContainer>
explicit SearchServer(const StringContainer& stop_words)
: stop_words_(MakeUniqueNonEmptyStrings(stop_words)) // Extract non-empty stop words
{
if (!all_of(stop_words_.begin(), stop_words_.end(), IsValidWord)) {
throw invalid_argument("Some of stop words are invalid"s);
}
}
explicit SearchServer(const string& stop_words_text)
: SearchServer(
SplitIntoWords(stop_words_text)) // Invoke delegating constructor from string container
{
}
void AddDocument(int document_id, const string& document, DocumentStatus status,
const vector<int>& ratings) {
if ((document_id < 0) || (documents_.count(document_id) > 0)) {
throw invalid_argument("Invalid document_id"s);
}
const auto words = SplitIntoWordsNoStop(document);
const double inv_word_count = 1.0 / words.size();
for (const string& word : words) {
word_to_document_freqs_[word][document_id] += inv_word_count;
}
documents_.emplace(document_id, DocumentData{ComputeAverageRating(ratings), status});
document_ids_.push_back(document_id);
}
template <typename DocumentPredicate>
vector<Document> FindTopDocuments(const string& raw_query,
DocumentPredicate document_predicate) const {
const auto query = ParseQuery(raw_query);
auto matched_documents = FindAllDocuments(query, document_predicate);
sort(matched_documents.begin(), matched_documents.end(),
[](const Document& lhs, const Document& rhs) {
if (abs(lhs.relevance - rhs.relevance) < 1e-6) {
return lhs.rating > rhs.rating;
} else {
return lhs.relevance > rhs.relevance;
}
});
if (matched_documents.size() > MAX_RESULT_DOCUMENT_COUNT) {
matched_documents.resize(MAX_RESULT_DOCUMENT_COUNT);
}
return matched_documents;
}
vector<Document> FindTopDocuments(const string& raw_query, DocumentStatus status) const {
return FindTopDocuments(
raw_query, [status](int document_id, DocumentStatus document_status, int rating) {
return document_status == status;
});
}
vector<Document> FindTopDocuments(const string& raw_query) const {
return FindTopDocuments(raw_query, DocumentStatus::ACTUAL);
}
int GetDocumentCount() const {
return documents_.size();
}
int GetDocumentId(int index) const {
return document_ids_.at(index);
}
tuple<vector<string>, DocumentStatus> MatchDocument(const string& raw_query,
int document_id) const {
const auto query = ParseQuery(raw_query);
vector<string> matched_words;
for (const string& word : query.plus_words) {
if (word_to_document_freqs_.count(word) == 0) {
continue;
}
if (word_to_document_freqs_.at(word).count(document_id)) {
matched_words.push_back(word);
}
}
for (const string& word : query.minus_words) {
if (word_to_document_freqs_.count(word) == 0) {
continue;
}
if (word_to_document_freqs_.at(word).count(document_id)) {
matched_words.clear();
break;
}
}
return {matched_words, documents_.at(document_id).status};
}
private:
struct DocumentData {
int rating;
DocumentStatus status;
};
const set<string> stop_words_;
map<string, map<int, double>> word_to_document_freqs_;
map<int, DocumentData> documents_;
vector<int> document_ids_;
bool IsStopWord(const string& word) const {
return stop_words_.count(word) > 0;
}
static bool IsValidWord(const string& word) {
// A valid word must not contain special characters
return none_of(word.begin(), word.end(), [](char c) {
return c >= '\0' && c < ' ';
});
}
vector<string> SplitIntoWordsNoStop(const string& text) const {
vector<string> words;
for (const string& word : SplitIntoWords(text)) {
if (!IsValidWord(word)) {
throw invalid_argument("Word "s + word + " is invalid"s);
}
if (!IsStopWord(word)) {
words.push_back(word);
}
}
return words;
}
static int ComputeAverageRating(const vector<int>& ratings) {
if (ratings.empty()) {
return 0;
}
int rating_sum = 0;
for (const int rating : ratings) {
rating_sum += rating;
}
return rating_sum / static_cast<int>(ratings.size());
}
struct QueryWord {
string data;
bool is_minus;
bool is_stop;
};
QueryWord ParseQueryWord(const string& text) const {
if (text.empty()) {
throw invalid_argument("Query word is empty"s);
}
string word = text;
bool is_minus = false;
if (word[0] == '-') {
is_minus = true;
word = word.substr(1);
}
if (word.empty() || word[0] == '-' || !IsValidWord(word)) {
throw invalid_argument("Query word "s + text + " is invalid");
}
return {word, is_minus, IsStopWord(word)};
}
struct Query {
set<string> plus_words;
set<string> minus_words;
};
Query ParseQuery(const string& text) const {
Query result;
for (const string& word : SplitIntoWords(text)) {
const auto query_word = ParseQueryWord(word);
if (!query_word.is_stop) {
if (query_word.is_minus) {
result.minus_words.insert(query_word.data);
} else {
result.plus_words.insert(query_word.data);
}
}
}
return result;
}
// Existence required
double ComputeWordInverseDocumentFreq(const string& word) const {
return log(GetDocumentCount() * 1.0 / word_to_document_freqs_.at(word).size());
}
template <typename DocumentPredicate>
vector<Document> FindAllDocuments(const Query& query,
DocumentPredicate document_predicate) const {
map<int, double> document_to_relevance;
for (const string& word : query.plus_words) {
if (word_to_document_freqs_.count(word) == 0) {
continue;
}
const double inverse_document_freq = ComputeWordInverseDocumentFreq(word);
for (const auto [document_id, term_freq] : word_to_document_freqs_.at(word)) {
const auto& document_data = documents_.at(document_id);
if (document_predicate(document_id, document_data.status, document_data.rating)) {
document_to_relevance[document_id] += term_freq * inverse_document_freq;
}
}
}
for (const string& word : query.minus_words) {
if (word_to_document_freqs_.count(word) == 0) {
continue;
}
for (const auto [document_id, _] : word_to_document_freqs_.at(word)) {
document_to_relevance.erase(document_id);
}
}
vector<Document> matched_documents;
for (const auto [document_id, relevance] : document_to_relevance) {
matched_documents.push_back(
{document_id, relevance, documents_.at(document_id).rating});
}
return matched_documents;
}
};
ostream& operator<<(ostream& out, const Document& doc)
{
out<<"{ document_id = "s<<doc.id<<", relevance = "s<<doc.relevance<<", rating = "s<<doc.rating<<" }"s;
return out;
}
template<typename Iterator>
class IteratorRange{
public:
IteratorRange(Iterator beg, Iterator end):
beg_(beg),end_(end){}
auto begin() const{
return beg_;
}
auto end() const{
return end_;
}
size_t size() const{
return distance(beg_,end_);
}
private:
Iterator beg_;
Iterator end_;
};
template<typename Iterator>
ostream& operator<<(ostream& stream, const IteratorRange<Iterator>& range)
{
for (auto it=range.begin();it!=range.end();++it)
stream<<*it;
return stream;
}
template <typename Iterator>
class Paginator {
public:
Paginator(Iterator iter_begin,Iterator iter_end, size_t pagesize)
{//итератор - указатель на строку
/*for (Iterator page_begin=iter_begin, page_end=iter_begin; page_begin!= iter_end;page_begin=page_end)
{
page_end=next(page_begin,min(pagesize,static_cast<size_t>(distance(page_begin,iter_end))));
data.emplace_back(page_begin,page_end);
}*/
for (;iter_begin<iter_end;advance(iter_begin,pagesize))
{
size_t dist=distance(iter_begin,iter_end);
data.emplace_back(IteratorRange(iter_begin,iter_begin+min({pagesize,dist})));
}
}
//typename vector<IteratorRange<Iterator>>::iterator
auto begin() const{
return data.begin();
}
//typename vector<IteratorRange<Iterator>>::iterator
auto end() const{
return data.end();
}
size_t size() const{
return distance(data.begin(),data.end());
}
private:
vector<IteratorRange<Iterator>> data;
};
template<class CONT>
const auto Paginate(CONT search_documents,size_t pagesize)
{
return Paginator(begin(search_documents),end(search_documents),pagesize);
}
int main() {
SearchServer search_server("and with"s);
search_server.AddDocument(1, "funny pet and nasty rat"s, DocumentStatus::ACTUAL, {7, 2, 7});
search_server.AddDocument(2, "funny pet with curly hair"s, DocumentStatus::ACTUAL, {1, 2, 3});
search_server.AddDocument(3, "big cat nasty hair"s, DocumentStatus::ACTUAL, {1, 2, 8});
search_server.AddDocument(4, "big dog cat Vladislav"s, DocumentStatus::ACTUAL, {1, 3, 2});
search_server.AddDocument(5, "big dog hamster Borya"s, DocumentStatus::ACTUAL, {1, 1, 1});
const auto search_results = search_server.FindTopDocuments("curly dog"s);
int page_size = 2;
const auto pages = Paginate(search_results, page_size);
// Выводим найденные документы по страницам
for (auto page = pages.begin(); page != pages.end(); ++page) {
cout << *page << endl;
cout << "Page break"s << endl;
}
}

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