AdventOfCode2024/Aufgabe1/main.cpp

#include <iostream>
#include <vector>
#include <fstream>

std::vector<std::string> readTextFromFile(const std::string& fileName) {
    std::vector<std::string> lines;
    std::ifstream file(fileName);
    if (!file) {  // Überprüft, ob die Datei geöffnet werden konnte
        std::cerr << "Fehler: Datei konnte nicht geöffnet werden: " << fileName << std::endl;
        return lines;
    }
    std::string s;
    while(getline(file, s)) {
        lines.push_back(s);
    }
    return lines;
}

std::string removeExtraSpaces(const std::string& input) {
    std::string result;
    bool inSpace = false;

    for(char c: input) {
        if(c == ' ') {
            if(!inSpace) {
                result += c;
                inSpace = true;
            }
        } else {
            result += c;
            inSpace = false;
        }
    }
    return result;
}

std::vector<std::string> splitString(const std::string& input, char ch) {
    std::vector<std::string> splittedString;
    size_t pos = input.find(ch);
    size_t initialPos = 0;

    while(pos != std::string::npos) {
        splittedString.push_back(input.substr(initialPos, pos - initialPos));
        initialPos = pos + 1;
        pos = input.find(ch, initialPos);
    }

    splittedString.push_back(input.substr(initialPos, std::min(pos, input.size()) - initialPos));

    return splittedString;
}

std::tuple<std::vector<int>, std::vector<int>> parseInputVector(std::vector<std::string> inputVector) {
    std::vector<int> leftArray;
    std::vector<int> rightArray;

    for(const auto &inputString : inputVector) {
        std::string trimmedInputString = removeExtraSpaces(inputString);
        std::vector<std::string> splittedString = splitString(trimmedInputString, ' ');
        std::cout << "Splittted-Size: " << splittedString.size() << std::endl;

        int leftValue = std::stoi(splittedString.at(0));
        int rightValue = std::stoi(splittedString.at(1));

        leftArray.push_back(leftValue);
        rightArray.push_back(rightValue);
    }
    return std::make_tuple(leftArray, rightArray);
}

std::vector<int> merge(const std::vector<int>& left, const  std::vector<int>& right) {
    std::vector<int> resultingList;
    size_t i = 0, j = 0;
    while(i < left.size() && j < right.size()) {
        if(left[i] <= right[j]) {
            resultingList.push_back(left[i]);
            i++;
        } else {
            resultingList.push_back(right[j]);
            j++;
        }
    }

    while(i < left.size()) {
        resultingList.push_back(left[i]);
        i++;
    }

    while(j < right.size()) {
        resultingList.push_back(right[j]);
        j++;
    }

    return resultingList;
}

std::vector<int> mergeSort(std::vector<int>& vec) {
    if(vec.size() <= 1) return vec;

    int mid = vec.size()/2;
    std::vector<int> leftList(vec.begin(), vec.begin() + mid);
    std::vector<int> rightList(vec.begin() + mid, vec.end());

    return merge(mergeSort(leftList), mergeSort(rightList));
}

int solve(std::vector<int>& left, std::vector<int>& right) {
    std::vector<int> sortedLeft = mergeSort(left);
    std::vector<int> sortedRight = mergeSort(right);

    int sum = 0;
    if(sortedLeft.size() == sortedRight.size()) {
        for(int i=0; i<sortedLeft.size(); i++) {
            sum += std::abs(sortedLeft.at(i) - sortedRight.at(i));
        }
    }
    return sum;
}

int main() {
    std::string inputFile = "../input.txt";
    std::vector<std::string> input = readTextFromFile(inputFile);
    auto [leftArray, rightArray] = parseInputVector(input);

    int result = solve(leftArray, rightArray);
    std::cout << "The result is: " << result << std::endl;
    return 0;
}