import java.io.*;

/*

* A BitInputStream lets you read in the contents of a binary file in

* units of: one bit (a single binary digit), one byte (8 bits), and

* one 4-byte word (32 bits). The bits that form a byte or a word do

* not have to be byte aligned.

*/

public class BitInputStream implements AutoCloseable {

private byte[] bytes;

private int index;

public BitInputStream(File in) throws FileNotFoundException, IOException {

this(new FileInputStream(in));

}

public BitInputStream(FileInputStream fileInputStream) throws IOException {

DataInputStream in = new DataInputStream(fileInputStream);

int size = in.available();

this.bytes = new byte[size];

this.index = 0;

in.read(bytes);

in.close();

}

/*

* Returns the file size as a count of bytes.

*/

public int size() {

return bytes.length;

}

public byte[] allBytes() {

return bytes;

}

public int readBit() throws IOException {

byte b = bytes[index / 8];

int offset = index % 8;

final int mask = 1 << 7;

++index;

return (b & (mask >>> offset)) == 0 ? 0 : 1;

}

public int readByte() throws IOException {

byte value = 0;

for (int i = 0; i < 8; ++i) {

value <<= 1;

value |= readBit();

}

return value & 0xFF;

}

public int readInt() throws IOException {

int value = readByte();

value = (value << 8) | readByte();

value = (value << 8) | readByte();

value = (value << 8) | readByte();

return value;

}

public void close() throws IOException {

// intentionally left blank

}

}