MixedRadixNumber.java Source code

Introduction

Here is the source code for MixedRadixNumber.java

Source

//package aima.core.util.math;

import java.util.List;

/**
 * @author Ciaran O'Reilly see:
 *         http://demonstrations.wolfram.com/MixedRadixNumberRepresentations/
 *         for useful example.
 */
public class MixedRadixNumber extends Number {
    //
    private static final long serialVersionUID = 1L;
    //
    private long value = 0L;
    private long maxValue = 0L;
    private int[] radixs = null;
    private int[] currentNumeralValue = null;
    private boolean recalculate = true;

    public MixedRadixNumber(long value, int[] radixs) {
        this.value = value;
        this.radixs = new int[radixs.length];
        System.arraycopy(radixs, 0, this.radixs, 0, radixs.length);
        calculateMaxValue();
    }

    public MixedRadixNumber(long value, List<Integer> radixs) {
        this.value = value;
        this.radixs = new int[radixs.size()];
        for (int i = 0; i < radixs.size(); i++) {
            this.radixs[i] = radixs.get(i);
        }
        calculateMaxValue();
    }

    public long getMaxAllowedValue() {
        return maxValue;
    }

    public boolean increment() {
        if (value < maxValue) {
            value++;
            recalculate = true;
            return true;
        }

        return false;
    }

    public boolean decrement() {
        if (value > 0) {
            value--;
            recalculate = true;
            return true;
        }
        return false;
    }

    public int getCurrentNumeralValue(int atPosition) {
        if (atPosition >= 0 && atPosition < radixs.length) {
            if (recalculate) {
                long quotient = value;
                for (int i = 0; i < radixs.length; i++) {
                    if (0 != quotient) {
                        currentNumeralValue[i] = (int) quotient % radixs[i];
                        quotient = quotient / radixs[i];
                    } else {
                        currentNumeralValue[i] = 0;
                    }

                }
                recalculate = false;
            }
            return currentNumeralValue[atPosition];
        }
        throw new IllegalArgumentException("Argument atPosition must be >=0 and < " + radixs.length);
    }

    //
    // START-Number
    @Override
    public int intValue() {
        return (int) longValue();
    }

    @Override
    public long longValue() {
        return value;
    }

    @Override
    public float floatValue() {
        return longValue();
    }

    @Override
    public double doubleValue() {
        return longValue();
    }

    // END-Number
    //

    @Override
    public String toString() {
        StringBuilder sb = new StringBuilder();

        for (int i = 0; i < radixs.length; i++) {
            sb.append("[");
            sb.append(this.getCurrentNumeralValue(i));
            sb.append("]");
        }

        return sb.toString();
    }

    //
    // PRIVATE
    //
    private void calculateMaxValue() {
        if (0 == radixs.length) {
            throw new IllegalArgumentException("At least 1 radix must be defined.");
        }
        for (int i = 0; i < radixs.length; i++) {
            if (radixs[i] < 2) {
                throw new IllegalArgumentException("Invalid radix, must be >= 2");
            }
        }

        // Calcualte the maxValue allowed
        maxValue = radixs[0];
        for (int i = 1; i < radixs.length; i++) {
            maxValue *= radixs[i];
        }
        maxValue -= 1;

        if (value > maxValue) {
            throw new IllegalArgumentException("The value [" + value
                    + "] cannot be represented with the radixs provided, max value is " + maxValue);
        }

        currentNumeralValue = new int[radixs.length];
    }
}