QuestionB.java

package Q10_11_Peaks_and_Valleys;

import CtCILibrary.AssortedMethods;

public class QuestionB {
	public static void swap(int[] array, int left, int right) {
		int temp = array[left];
		array[left] = array[right];
		array[right] = temp;
	}
	
	public static void sortValleyPeak(int[] array) {
		for (int i = 1; i < array.length; i += 2) {
			int biggestIndex = maxIndex(array, i - 1, i, i + 1);
			if (i != biggestIndex) {
				swap(array, i, biggestIndex);
			}
		}
	}	
	
	public static int maxIndex(int[] array, int a, int b, int c) {
		int len = array.length;
		int aValue = a >= 0 && a < len ? array[a] : Integer.MIN_VALUE; 
		int bValue = b >= 0 && b < len ? array[b] : Integer.MIN_VALUE; 
		int cValue = c >= 0 && c < len ? array[c] : Integer.MIN_VALUE; 
		
		int max = Math.max(aValue, Math.max(bValue, cValue));
		
		if (aValue == max) {
			return a;
		} else if (bValue == max) {
		 	return b;
		} else {
			return c;
		}
	}

	public static void main(String[] args) {
		int[] array = {48, 40, 31, 62, 28, 21, 64, 40, 23, 17};
		System.out.println(AssortedMethods.arrayToString(array));
		sortValleyPeak(array);
		System.out.println(AssortedMethods.arrayToString(array));
		System.out.println(Tester.confirmValleyPeak(array));
	}

}