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@JustSlavic
Created December 19, 2019 09:45
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#include <iostream>
#include <fstream>
#include <string>
#include <functional>
#include <algorithm>
#include <vector>
#include <map>
class Dictionary {
public:
using value_t = std::pair<std::string, size_t>;
void push(const std::string& value) {
container[value]++;
}
std::vector<value_t> to_vector() const {
std::vector<value_t> result;
for (auto&& pair : container) { result.emplace_back(pair); }
std::sort(result.begin(), result.end(), cmp);
return result;
}
private:
std::function<bool(const value_t&, const value_t&)>
cmp = [](const value_t& lhs, const value_t& rhs) -> bool {
if (lhs.second == rhs.second) {
return lhs.first < rhs.first;
}
return lhs.second > rhs.second;
};
std::map<std::string, size_t> container;
};
void apply_to_words(std::istream& input, const std::function<void(std::string&)>& callback) {
std::string buffer;
while (!input.eof()) {
char c = input.get();
if (std::isalpha(c)) {
buffer.push_back(std::tolower(c));
} else if (!buffer.empty()) {
callback(buffer);
buffer.clear();
}
}
if (!buffer.empty()) {
callback(buffer);
}
}
std::vector<Dictionary::value_t> count_words(std::istream& input) {
Dictionary dict;
apply_to_words(input, [&dict](std::string& word) { dict.push(word); });
return dict.to_vector();
}
void push_output(std::ostream& output, const std::vector<Dictionary::value_t>& data) {
for (auto&& pair : data) {
output << pair.first << " - " << pair.second << std::endl;
}
}
int main(int argc, char** argv) {
if (argc < 3) {
std::cout << "usage: freq <input file> <output file>" << std::endl;
return EXIT_FAILURE;
}
std::ifstream input(argv[1]);
if (!input.is_open()) {
std::cerr << "Cannot open the input file";
return 1;
}
std::ofstream output(argv[2]);
if (!output.is_open()) {
std::cerr << "Cannot open the output file";
return 1;
}
auto result = count_words(input);
push_output(output, result);
return EXIT_SUCCESS;
}
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