Java Fast I/O template along-with an example

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1

Can someone provide a template to perform really fast I/O using java as many problems require it?

2

For all of those who want answer, I found the following. It is from a submission by Egor .

class InputReader {

private InputStream stream;
private byte[] buf = new byte[1024];
private int curChar;
private int numChars;
private SpaceCharFilter filter;

public InputReader(InputStream stream) {
	this.stream = stream;
}

public int read() {
	if (numChars == -1)
		throw new InputMismatchException();
	if (curChar >= numChars) {
		curChar = 0;
		try {
			numChars = stream.read(buf);
		} catch (IOException e) {
			throw new InputMismatchException();
		}
		if (numChars <= 0)
			return -1;
	}
	return buf[curChar++];
}

public String readString() {
	int c = read();
	while (isSpaceChar(c))
		c = read();
	StringBuilder res = new StringBuilder();
	do {
		if (Character.isValidCodePoint(c))
			res.appendCodePoint(c);
		c = read();
	} while (!isSpaceChar(c));
	return res.toString();
}

public int readInt() {
	int c = read();
	while (isSpaceChar(c))
		c = read();
	int sgn = 1;
	if (c == '-') {
		sgn = -1;
		c = read();
	}
	int res = 0;
	do {
		if (c < '0' || c > '9')
			throw new InputMismatchException();
		res *= 10;
		res += c - '0';
		c = read();
	} while (!isSpaceChar(c));
	return res * sgn;
}

public boolean isSpaceChar(int c) {
	if (filter != null)
		return filter.isSpaceChar(c);
	return isWhitespace(c);
}

public static boolean isWhitespace(int c) {
	return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
}

public char readCharacter() {
	int c = read();
	while (isSpaceChar(c))
		c = read();
	return (char) c;
}

public interface SpaceCharFilter {
	public boolean isSpaceChar(int ch);
}
}

class OutputWriter {
private final PrintWriter writer;

public OutputWriter(OutputStream outputStream) {
	writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(
			outputStream)));
}

public void close() {
	writer.close();
}

public void printLine(long i) {
	writer.println(i);
}

public void printLine(int i) {
	writer.println(i);
}
}

class IOUtils {

public static char[] readCharArray(InputReader in, int size) {
	char[] array = new char[size];
	for (int i = 0; i < size; i++)
		array[i] = in.readCharacter();
	return array;
}

public static char[][] readTable(InputReader in, int rowCount,
		int columnCount) {
	char[][] table = new char[rowCount][];
	for (int i = 0; i < rowCount; i++)
		table[i] = readCharArray(in, columnCount);
	return table;
}

}

class ArrayUtils {

public static void fill(int[][] array, int value) {
	for (int[] row : array)
		Arrays.fill(row, value);
}

}

class MiscUtils {
public static final int[] DX4 = { 1, 0, -1, 0 };
public static final int[] DY4 = { 0, -1, 0, 1 };

public static boolean isValidCell(int row, int column, int rowCount,
		int columnCount) {
	return row >= 0 && row < rowCount && column >= 0
			&& column < columnCount;
}

}
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