#include <iostream>
#include <fstream>
#include <string>

// Replaces all standalone occurrences of oldNumber with newNumber in the given file
bool replaceNumberInFile(const std::string& filename, const std::string& oldNumber, const std::string& newNumber) {
    std::ifstream inFile(filename);
    if (!inFile.is_open()) {
        std::cerr << "Cannot open file for reading: " << filename << "\n";
        return false;
    }

    std::string modifiedContent;
    std::string line;

    while (std::getline(inFile, line)) {
        size_t pos = line.find(oldNumber);
        while (pos != std::string::npos) {
            // Ensure match is a full number (not part of another number)
            bool validStart = (pos == 0 || !isdigit(line[pos - 1]));
            bool validEnd = (pos + oldNumber.size() == line.size() || !isdigit(line[pos + oldNumber.size()]));

            if (validStart && validEnd) {
                line.replace(pos, oldNumber.length(), newNumber);
                pos = line.find(oldNumber, pos + newNumber.length());
            } else {
                pos = line.find(oldNumber, pos + 1);
            }
        }
        modifiedContent += line + "\n";
    }

    inFile.close();

    std::ofstream outFile(filename);
    if (!outFile.is_open()) {
        std::cerr << "Cannot open file for writing: " << filename << "\n";
        return false;
    }

    outFile << modifiedContent;
    outFile.close();

    return true;
}