aoc2024 day 2

#include <iostream>
#include <fstream>
#include <sstream>
#include <vector>
#include <cmath>

int main() {
    std::ifstream inputFile("aoc24.txt");
    if (!inputFile) {
        std::cerr << "Error: Could not open file!" << std::endl;
        return 1;
    }

    std::vector<std::vector<int>> dataset;
    std::string line;

    // Read the dataset from the file
    while (std::getline(inputFile, line)) {
        if (line.empty()) continue;

        std::istringstream lineStream(line);
        std::vector<int> row;
        int number;

        while (lineStream >> number) {
            row.push_back(number);
        }

        if (!row.empty()) {
            dataset.push_back(row);
        }
    }

    inputFile.close();

    int counter = 0; // Counter for valid rows

    // Process each row in the dataset
    for (const auto& row : dataset) {
        if (row.size() < 2) continue; // Skip rows with fewer than 2 elements

        bool ascend = true;
        bool descend = true;
        bool safeDiffer = true;

        // Check the row's validity without removing any element
        for (size_t j = 0; j < row.size() - 1; ++j) {
            if (row[j] < row[j + 1]) {
                descend = false;
            }
            if (row[j] > row[j + 1]) {
                ascend = false;
            }
            int distance = abs(row[j] - row[j + 1]);
            if (distance < 1 || distance >= 4) {
                safeDiffer = false;
            }
        }

        // If the row is valid without any removal, increment the counter
        if (safeDiffer && (ascend || descend)) {
            ++counter;
            continue;  // Skip the pop-checking part for this row
        }
        //flag
        bool validVariation = false;
        // Now check if removing any one element makes the row valid
        for (size_t pop = 0; pop < row.size(); ++pop) {
            std::vector<int> row_pop = row;  // Copy the original row
            row_pop.erase(row_pop.begin() + pop);  // Remove one element

            // Flags to track validity for the modified row (reset each time)
            ascend = true;
            descend = true;
            safeDiffer = true;
            //pop debug


            // Check the validity of the row after one element is removed
            for (size_t j = 0; j < row_pop.size() - 1; ++j) {
                if (row_pop[j] < row_pop[j + 1]) {
                    descend = false;
                }
                if (row_pop[j] > row_pop[j + 1]) {
                    ascend = false;
                }
                int distance = abs(row_pop[j] - row_pop[j + 1]);
                if (distance < 1 || distance >= 4) {
                    safeDiffer = false;
                }
            }

            // If the modified row is valid, increment the counter and break
            if (safeDiffer && (ascend || descend)) {
                ++counter;
                break;  // Exit the loop as we found a valid modified row
            }
        }
    }

    std::cout << "Number of valid rows: " << counter << std::endl;

    return 0;
}