Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
import java.math.BigInteger;

public class Main {
    private static final byte[] EMPTY_BYTES = new byte[0];

    public static byte[] generateNaf(BigInteger k) {
        if (k.signum() == 0) {
            return EMPTY_BYTES;
        }

        BigInteger _3k = k.shiftLeft(1).add(k);

        int digits = _3k.bitLength() - 1;
        byte[] naf = new byte[digits];

        BigInteger diff = _3k.xor(k);

        for (int i = 1; i < digits; ++i) {
            if (diff.testBit(i)) {
                naf[i - 1] = (byte) (k.testBit(i) ? -1 : 1);
                ++i;
            }
        }

        naf[digits - 1] = 1;

        return naf;
    }
}