BitArray.cpp

class BitArray {
public:
    BitArray(unsigned capacity) {
        bit_capacity = capacity;
        byte_capacity = capacity / 8 + 1;
        data = new char[capacity];
        memset(data, 0, byte_capacity);
    }
    
    ~BitArray() {
        delete[] data;
    }
    
    void set(size_t pos, bool val = true) {
        if (val)
            data[getBytePos(pos)] |= 1 << getBitPosInByte(pos);
        else
            data[getBytePos(pos)] &= ~(1 << getBitPosInByte(pos));
    }
    
    bool test(size_t pos) {
        return (data[getBytePos(pos)] & 1 << getBitPosInByte(pos)) != 0;
    }
    
private:
    int getBytePos(size_t pos) {
        return pos / 8; // pos >> 3
    }

    int getBitPosInByte(size_t pos) {
        return pos % 8;
    }

private:
    char *data;
    int bit_capacity;
    int byte_capacity;
};