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AdventOfCode2023/pb_1/problem_1.cpp
2024-01-17 21:02:28 +01:00

240 lines
9.2 KiB
C++

//
// Created by postaron on 06/12/23.
//
#include "problem_1.hpp"
#include <array>
#include <string>
#include <string_view>
#include <optional>
#include <unordered_map>
#include <vector>
#include <fstream>
#include <iostream>
#include <format>
namespace pb1 {
using namespace std::string_view_literals;
constexpr std::string_view digits = "0123456789";
constexpr std::array digitLetters{
"one"sv,
"two"sv,
"three"sv,
"four"sv,
"five"sv,
"six"sv,
"seven"sv,
"eight"sv,
"nine"sv,
};
const std::unordered_map<std::string_view, char> numbersSet{
{ "one"sv, '1' },
{ "two"sv, '2' },
{ "three"sv, '3' },
{ "four"sv, '4' },
{ "five"sv, '5' },
{ "six"sv, '6' },
{ "seven"sv, '7' },
{ "eight"sv, '8' },
{ "nine"sv, '9' },
};
std::optional<std::ifstream> read_file(const fs::path &problemFile) noexcept {
std::ifstream file(problemFile);
if (!file.is_open()) {
const auto error_state = file.rdstate();
switch (error_state) {
case std::ios::badbit:
std::cerr << "Fatal I/O error occurred.\n";
break;
case std::ios::eofbit:
std::cerr << "End of file reached.\n";
break;
case std::ios::failbit:
std::cerr << "Non-fatal I/O error occurred.\n";
break;
default:
std::cerr << "impossible to reach.\n";
break;
}
const auto path_string = problemFile.string();
const auto msg = std::format("Failed to open file {}: ", path_string);
std::perror(msg.c_str());
return std::nullopt;
}
return file;
}
void part1(const std::string_view &toSearch, std::size_t &result) noexcept {
const auto first_digit_pos = toSearch.find_first_of(digits);
if (first_digit_pos == std::string::npos) {
return;
}
const auto second_part = toSearch.substr(first_digit_pos);
const auto second_digit_pos = second_part.find_last_of(digits) + first_digit_pos;
result += (toSearch[first_digit_pos] - '0') * 10 + (toSearch[second_digit_pos] - '0');
}
std::size_t solve_problem_part1(const fs::path &problemFile) {
auto file_option = read_file(problemFile);
if (!file_option) {
return 0;
}
std::ifstream &file = *file_option;
std::size_t result = 0;
for (std::string line; std::getline(file, line);) {
part1(line, result);
}
return result;
}
void part2(const std::string_view &toSearch, std::vector<std::string> &splittedLine, std::size_t &result) noexcept {
std::string line_with_numbers, word;
line_with_numbers.reserve(toSearch.size());
word.reserve(sizeof("seven") - 1);
for (int i = 0; i < toSearch.size(); ++i) {
const std::uint32_t nb_characters_remaining = toSearch.size() - i;
switch (toSearch[i]) {
case 'o': {
if (nb_characters_remaining >= digitLetters[0].size()) {
word.append(toSearch.substr(i, digitLetters[0].size()));
if (numbersSet.contains(word)) {
line_with_numbers.push_back(numbersSet.at(word));
}
}
word.clear();
}
break;
case 't': {
if (nb_characters_remaining >= digitLetters[1].size()) {
// TODO: problème si on a two mais là ça ajoute + de caractère…
const auto number_two = toSearch.substr(i, digitLetters[1].size());
const auto number_three = [&]() -> std::string_view {
const auto tmp = toSearch.substr(i);
if (tmp.size() <= digitLetters[2].size()) {
return toSearch.substr(i);
} else {
return toSearch.substr(i, digitLetters[2].size());
}
}();
if (numbersSet.contains(number_two) or numbersSet.contains(number_three)) {
word.append(numbersSet.contains(number_two) ? number_two : number_three);
line_with_numbers.push_back(numbersSet.at(word));
}
}
word.clear();
}
break;
case 'f': {
// length five and four are equal
if (nb_characters_remaining < digitLetters[3].size()) {
line_with_numbers.append(toSearch.substr(i));
continue;
}
word.append(toSearch.substr(i, digitLetters[3].size()));
if (!numbersSet.contains(word)) {
const auto pos = word.find_first_of(digits);
if (pos != std::string::npos) {
line_with_numbers.push_back(word[pos]);
}
} else {
line_with_numbers.push_back(numbersSet.at(word));
}
word.clear();
}
break;
case 's': {
if (nb_characters_remaining < digitLetters[6].size()) {
line_with_numbers.append(toSearch.substr(i));
continue;
}
const auto number_six = toSearch.substr(i, digitLetters[5].size());
const auto number_seven = toSearch.substr(i, digitLetters[6].size());
if (!numbersSet.contains(number_six) and !numbersSet.contains(number_seven)) {
const auto pos = number_seven.find_first_of(digits);
if (pos != std::string::npos) {
line_with_numbers.push_back(word[pos]);
}
} else {
line_with_numbers.push_back(numbersSet.at(word));
}
word.clear();
}
break;
case 'e': {
if (nb_characters_remaining < digitLetters[7].size()) {
line_with_numbers.append(toSearch.substr(i));
continue;
}
word.append(toSearch.substr(i, digitLetters[7].size()));
if (!numbersSet.contains(word)) {
const auto pos = word.find_first_of(digits);
if (pos != std::string::npos) {
line_with_numbers.push_back(word[pos]);
}
} else {
line_with_numbers.push_back(numbersSet.at(word));
}
word.clear();
}
break;
case 'n': {
if (nb_characters_remaining < digitLetters.back().size()) {
line_with_numbers.append(toSearch.substr(i));
continue;
}
word.append(toSearch.substr(i, digitLetters.back().size()));
if (!numbersSet.contains(word)) {
const auto pos = word.find_first_of(digits);
if (pos != std::string::npos) {
line_with_numbers.push_back(word[pos]);
}
} else {
line_with_numbers.push_back(numbersSet.at(word));
}
word.clear();
}
break;
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
line_with_numbers.push_back(toSearch[i]);
break;
default:
if ((toSearch[i] - '0') < 10) {
line_with_numbers.push_back(toSearch[i]);
}
break;
}
}
if (!line_with_numbers.empty()) {
result += (line_with_numbers.front() - '0') * 10 + (line_with_numbers.back() - '0');
}
}
std::size_t solve_problem_part2(const fs::path &problemFile) {
auto file_option = read_file(problemFile);
if (!file_option) {
return 0;
}
std::ifstream &file = *file_option;
std::vector<std::string> splitted_line;
std::size_t result = 0;
for (std::string line; std::getline(file, line);) {
part2(line, splitted_line, result);
splitted_line.clear();
}
return result;
}
}