| 1 | package de.ugoe.cs.util;
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| 2 |
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| 3 | /**
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| 4 | * <p>
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| 5 | * Helper class that provides methods to simplify working with arrays.
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| 6 | * </p>
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| 7 | *
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| 8 | * @author Steffen Herbold
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| 9 | * @version 1.0
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| 10 | */
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| 11 | final public class ArrayTools {
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| 12 |
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| 13 | /**
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| 14 | * <p>
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| 15 | * Finds the first occurrence of an object inside an array.
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| 16 | * </p>
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| 17 | * <p>
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| 18 | * In case {@code other==null}, the first occurrence of a {@code null} value
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| 19 | * in the array is returned.
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| 20 | * </p>
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| 21 | *
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| 22 | * @param array
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| 23 | * the array
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| 24 | * @param other
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| 25 | * the object
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| 26 | * @return index of the object if found, -1 otherwise
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| 27 | */
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| 28 | public static int findIndex(Object[] array, Object other) {
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| 29 | int retVal = -1;
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| 30 | for (int i = 0; i < array.length && retVal == -1; i++) {
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| 31 | if (other != null) {
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| 32 | if (array[i] != null && array[i].equals(other)) {
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| 33 | retVal = i;
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| 34 | }
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| 35 | } else {
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| 36 | if (array[i] == null) {
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| 37 | retVal = i;
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| 38 | }
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| 39 | }
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| 40 | }
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| 41 | return retVal;
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| 42 | }
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| 43 |
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| 44 | /**
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| 45 | * <p>
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| 46 | * Finds the highest element in an array. If multiple elements have the
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| 47 | * maximum value, the index of the first one is returned; null-values are
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| 48 | * ignored. In case the parameter array is null, has length 0 or contains
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| 49 | * only null-values, -1 is returned.
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| 50 | * </p>
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| 51 | *
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| 52 | * @param <T>
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| 53 | * @param array
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| 54 | * the array
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| 55 | * @return index of the element with the highest value, -1 in case of an
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| 56 | * invalid parameter
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| 57 | */
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| 58 | @SuppressWarnings("unchecked")
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| 59 | public static <T> int findMax(Comparable<T>[] array) {
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| 60 | int maxIndex = -1;
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| 61 | T maxElement = null;
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| 62 | if (array != null) {
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| 63 | for (int i = 0; i < array.length; i++) {
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| 64 | if (array[i] != null) {
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| 65 | if (maxElement == null
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| 66 | || array[i].compareTo(maxElement) > 0) {
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| 67 | maxElement = (T) array[i];
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| 68 | maxIndex = i;
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| 69 | }
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| 70 | }
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| 71 | }
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| 72 | }
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| 73 | return maxIndex;
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| 74 | }
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| 75 |
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| 76 | /**
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| 77 | * <p>
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| 78 | * Finds the lowest element in an array. If multiple elements have the
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| 79 | * minimal value, the index of the first one is returned; null-values are
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| 80 | * ignored. In case the parameter array is null, has length 0 or contains
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| 81 | * only null-values, -1 is returned.
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| 82 | * </p>
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| 83 | *
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| 84 | * @param <T>
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| 85 | * @param array
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| 86 | * the array
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| 87 | * @return index of the element with the lowest value, -1 in case of an
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| 88 | * invalid parameter
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| 89 | */
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| 90 | @SuppressWarnings("unchecked")
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| 91 | public static <T> int findMin(Comparable<T>[] array) {
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| 92 | int maxIndex = -1;
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| 93 | T maxElement = null;
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| 94 | if (array != null) {
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| 95 | for (int i = 0; i < array.length; i++) {
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| 96 | if (array[i] != null) {
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| 97 | if (maxElement == null
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| 98 | || array[i].compareTo(maxElement) < 0) {
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| 99 | maxElement = (T) array[i];
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| 100 | maxIndex = i;
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| 101 | }
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| 102 | }
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| 103 | }
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| 104 | }
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| 105 | return maxIndex;
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| 106 | }
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| 107 | }
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