Miscellany

float* constructHistogram (istream& in){    float* histogram = new float[0x100];        uchar c;    while (c = in.get(), in)    {        histogram[c]++;    }        in.seekg(ios::beg);    //in.clear();    cin.clear(istream::eofbit);        return histogram;}void usage (char* progname){    cerr << "Usage:\t" << progname << " -e infile outfile\n";    cerr << "\t" << progname << " -d infile outfile\n\n";    cerr << "Use the -e option to encode, and -d to decode.\n";}int main (int argc, char** argv){    if (argc != 4)    {        usage(argv[0]);        return 1;    }        ifstream fin(argv[2]);    ofstream fout(argv[3]);        if (argv[1][1] == 'e')    {        float* freqs;        if (-1 == fin.tellg())            // this file does not support seeking, so use fallback frequencies            freqs = fallbackFreqs;        else            freqs = constructHistogram(fin);                HuffmanCoder hc(freqs);                if (freqs != fallbackFreqs)            delete[] freqs;                string text;                deque<bool> huffman_stream = hc.start();                while (fin)        {            char buf[1024];            fin.read(buf, sizeof(buf));            int buflen = fin.gcount();                        cerr << buflen << endl;                        string stringbuf(buf, buflen);            hc.write(huffman_stream, stringbuf);        }                hc.flush(huffman_stream, fout);    }    else if (argv[1][1] == 'd')    {        HuffmanDecoder dc(fin);        fout << dc.decode();    }    else    {        usage(argv[0]);        return 1;    }}