/**
 * Exercise 12.6 p 471
 */

public class Exercise126 {

    // Make all methods public to allow testing

    /**
     * a.
     * modifies names
     * postcondition
     * all items in names are assigned the letter 'R'
     */
    public void makeAllRs(char[] names)
    {
        if (names==null) return; // just to be safe in all cases

        for(int i=0; i<names.length; i++)
            names[i]='R';
    }

    /**
     * precondition
     *  arr.length>=2
     * modifies
     *  arr[0], arr[1]
     * postcondition
     *  the values in arr[0] and arr[1] are swapped from their old values
     */
    public void swapFirstTwo(double[] arr)
    {
        double temp = arr[0];
        arr[0] = arr[1];
        arr[1] = temp;
    }

    /**
     * precondition
     *  dArray.length >=1
     * postcondition
     *  result is the largest double value of any item in the array
     */
    public double biggestValue(double[] dArray)
    {
        double max = dArray[0];
        for(int i=1; i<dArray.length; i++)
            if (dArray[i]>max) max = dArray[i];

        return max;
    }

    /**
     * precondition
     *  dArray.length >= 1
     * postcondition
     *  result is the index of the largest valued item in the array
     */
    public int biggestIndex(double[] dArray)
    {
        int maxIndex = 0;
        for(int i=1; i<dArray.length; i++)
            if (dArray[i]>dArray[maxIndex]) maxIndex = i;

        return maxIndex;
    }

    /**
     * precondition
     *  target.length == source.length
     * modifies
     *  target
     * postcondition
     *  the item values in target are reversed in order from source
     */
    public void copyReversed(char[] source, char[] target)
    {
        for(int i=0; i<source.length; i++)
            target[source.length-i-1] = source[i];
    }
}