[927] | 1 | // Copyright 2012 Georg-August-Universität Göttingen, Germany
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| 2 | //
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| 3 | // Licensed under the Apache License, Version 2.0 (the "License");
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| 4 | // you may not use this file except in compliance with the License.
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| 5 | // You may obtain a copy of the License at
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| 6 | //
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| 7 | // http://www.apache.org/licenses/LICENSE-2.0
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| 8 | //
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| 9 | // Unless required by applicable law or agreed to in writing, software
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| 10 | // distributed under the License is distributed on an "AS IS" BASIS,
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| 11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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| 12 | // See the License for the specific language governing permissions and
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| 13 | // limitations under the License.
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| 14 |
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[1] | 15 | package de.ugoe.cs.util;
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| 16 |
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[175] | 17 | /**
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| 18 | * <p>
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| 19 | * Helper class that provides methods to simplify working with arrays.
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| 20 | * </p>
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| 21 | *
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| 22 | * @author Steffen Herbold
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| 23 | * @version 1.0
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| 24 | */
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[1] | 25 | final public class ArrayTools {
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[175] | 26 |
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[1] | 27 | /**
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| 28 | * <p>
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[330] | 29 | * Private constructor to prevent initializing of the class.
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| 30 | * </p>
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| 31 | */
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| 32 | private ArrayTools() {
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| 33 |
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| 34 | }
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| 35 |
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| 36 | /**
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| 37 | * <p>
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[175] | 38 | * Finds the first occurrence of an object inside an array.
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[1] | 39 | * </p>
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| 40 | * <p>
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[175] | 41 | * In case {@code other==null}, the first occurrence of a {@code null} value
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| 42 | * in the array is returned.
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[1] | 43 | * </p>
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[175] | 44 | *
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| 45 | * @param array
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| 46 | * the array
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| 47 | * @param other
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| 48 | * the object
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[1] | 49 | * @return index of the object if found, -1 otherwise
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| 50 | */
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| 51 | public static int findIndex(Object[] array, Object other) {
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| 52 | int retVal = -1;
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[175] | 53 | for (int i = 0; i < array.length && retVal == -1; i++) {
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| 54 | if (other != null) {
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| 55 | if (array[i] != null && array[i].equals(other)) {
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[1] | 56 | retVal = i;
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| 57 | }
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| 58 | } else {
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[175] | 59 | if (array[i] == null) {
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[1] | 60 | retVal = i;
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| 61 | }
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| 62 | }
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| 63 | }
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| 64 | return retVal;
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| 65 | }
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[290] | 66 |
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| 67 | /**
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| 68 | * <p>
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| 69 | * Finds the highest element in an array. If multiple elements have the
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| 70 | * maximum value, the index of the first one is returned; null-values are
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| 71 | * ignored. In case the parameter array is null, has length 0 or contains
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| 72 | * only null-values, -1 is returned.
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| 73 | * </p>
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| 74 | *
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| 75 | * @param <T>
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| 76 | * @param array
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| 77 | * the array
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| 78 | * @return index of the element with the highest value, -1 in case of an
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| 79 | * invalid parameter
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| 80 | */
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| 81 | @SuppressWarnings("unchecked")
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| 82 | public static <T> int findMax(Comparable<T>[] array) {
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| 83 | int maxIndex = -1;
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| 84 | T maxElement = null;
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| 85 | if (array != null) {
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| 86 | for (int i = 0; i < array.length; i++) {
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| 87 | if (array[i] != null) {
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| 88 | if (maxElement == null
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| 89 | || array[i].compareTo(maxElement) > 0) {
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| 90 | maxElement = (T) array[i];
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| 91 | maxIndex = i;
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| 92 | }
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| 93 | }
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| 94 | }
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| 95 | }
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| 96 | return maxIndex;
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| 97 | }
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[1296] | 98 |
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| 99 | /**
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| 100 | * <p>
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| 101 | * Finds the highest element in an array. If multiple elements have the
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| 102 | * maximum value, the index of the first one is returned; null-values are
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| 103 | * ignored. In case the parameter array is null, has length 0 or contains
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| 104 | * only null-values, -1 is returned.
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| 105 | * </p>
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| 106 | *
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| 107 | * @param array
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| 108 | * the array
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| 109 | * @return index of the element with the highest value, -1 in case of an
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| 110 | * invalid parameter
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| 111 | */
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[1297] | 112 | public static int findMax(double[] array) {
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[1296] | 113 | int maxIndex = -1;
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[1298] | 114 | double maxElement = -Double.MAX_VALUE;
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[1296] | 115 | if (array != null) {
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| 116 | for (int i = 0; i < array.length; i++) {
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| 117 | if (array[i] > maxElement) {
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| 118 | maxElement = array[i];
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| 119 | maxIndex = i;
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| 120 | }
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| 121 | }
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| 122 | }
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| 123 | return maxIndex;
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| 124 | }
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[330] | 125 |
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[290] | 126 | /**
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| 127 | * <p>
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| 128 | * Finds the lowest element in an array. If multiple elements have the
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| 129 | * minimal value, the index of the first one is returned; null-values are
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| 130 | * ignored. In case the parameter array is null, has length 0 or contains
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| 131 | * only null-values, -1 is returned.
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| 132 | * </p>
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| 133 | *
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| 134 | * @param <T>
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| 135 | * @param array
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| 136 | * the array
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| 137 | * @return index of the element with the lowest value, -1 in case of an
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| 138 | * invalid parameter
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| 139 | */
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| 140 | @SuppressWarnings("unchecked")
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| 141 | public static <T> int findMin(Comparable<T>[] array) {
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| 142 | int maxIndex = -1;
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| 143 | T maxElement = null;
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| 144 | if (array != null) {
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| 145 | for (int i = 0; i < array.length; i++) {
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| 146 | if (array[i] != null) {
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| 147 | if (maxElement == null
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| 148 | || array[i].compareTo(maxElement) < 0) {
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| 149 | maxElement = (T) array[i];
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| 150 | maxIndex = i;
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| 151 | }
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| 152 | }
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| 153 | }
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| 154 | }
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| 155 | return maxIndex;
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| 156 | }
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[1] | 157 | }
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