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

int main(int argc, char* argv[]) {
    if (argc < 3) {
        std::cerr << "Usage: " << argv[0] << " <inputfile> <outputfile>\n";
        return 1;
    }

    std::ifstream infile(argv[1], std::ios::binary);
    if (!infile) {
        std::cerr << "Error opening input file.\n";
        return 1;
    }

    std::vector<char> buffer((std::istreambuf_iterator<char>(infile)),
        std::istreambuf_iterator<char>());
    infile.close();

    // Step 1: Replace ASCII 171 with 189
    /*
    for (auto& c : buffer) {
        if ((unsigned char)c == 171) {
            c = (char)189;
        }
    }
    */

    // Step 2: Remove form feed (ASCII 12) from the last 16 bytes only
    size_t size = buffer.size();
    size_t start = (size >= 16) ? size - 16 : 0;
    for (size_t i = start; i < size; ) {
        if ((unsigned char)buffer[i] == 12) {
            buffer.erase(buffer.begin() + i);
            size--;  // update size since vector shrinks
        }
        else {
            i++;
        }
    }

    std::ofstream outfile(argv[2], std::ios::binary);
    if (!outfile) {
        std::cerr << "Error opening output file.\n";
        return 1;
    }

    outfile.write(buffer.data(), buffer.size());
    outfile.close();

    //std::cout << "Processing complete. Output written to " << argv[2] << "\n";
    return 0;
}