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| 1 | +package org.korben.coding.basic.list; |
| 2 | + |
| 3 | +import java.util.Objects; |
| 4 | + |
| 5 | +/** |
| 6 | + * Korben's LinkedList |
| 7 | + * |
| 8 | + * Created by Korben on 18/02/2017. |
| 9 | + */ |
| 10 | +public class KDoubleLinkedList<T> implements KList<T> { |
| 11 | + |
| 12 | + private int size; |
| 13 | + |
| 14 | + private Node<T> head; |
| 15 | + |
| 16 | + private Node<T> last; |
| 17 | + |
| 18 | + public KDoubleLinkedList() { |
| 19 | + this.head = new Node<>(null); |
| 20 | + } |
| 21 | + |
| 22 | + @Override |
| 23 | + public int size() { |
| 24 | + return this.size; |
| 25 | + } |
| 26 | + |
| 27 | + @Override |
| 28 | + public boolean isEmpty() { |
| 29 | + return this.size == 0; |
| 30 | + } |
| 31 | + |
| 32 | + @Override |
| 33 | + public boolean contains(Object o) { |
| 34 | + Node node = this.head; |
| 35 | + while (node.next != null) { |
| 36 | + node = node.next; |
| 37 | + if (Objects.equals(node.data, o)) { |
| 38 | + return true; |
| 39 | + } |
| 40 | + } |
| 41 | + return false; |
| 42 | + } |
| 43 | + |
| 44 | + @Override |
| 45 | + public Object[] toArray() { |
| 46 | + return new Object[0]; |
| 47 | + } |
| 48 | + |
| 49 | + @Override |
| 50 | + public boolean add(T o) { |
| 51 | + if (this.last == null) { |
| 52 | + this.last = new Node<>(o); |
| 53 | + this.last.pre = this.head; |
| 54 | + this.head.next = this.last; |
| 55 | + } else { |
| 56 | + Node<T> oldLast = this.last; |
| 57 | + this.last = new Node<>(o); |
| 58 | + this.last.pre = oldLast; |
| 59 | + oldLast.next = this.last; |
| 60 | + } |
| 61 | + this.size++; |
| 62 | + return true; |
| 63 | + } |
| 64 | + |
| 65 | + @Override |
| 66 | + public boolean remove(T o) { |
| 67 | + Node node = this.head; |
| 68 | + while (node.next != null) { |
| 69 | + node = node.next; |
| 70 | + if (Objects.equals(node.data, o)) { |
| 71 | + node.pre.next = node.next; |
| 72 | + if (node.next != null) { |
| 73 | + node.next.pre = node.pre; |
| 74 | + } |
| 75 | + this.size--; |
| 76 | + return true; |
| 77 | + } |
| 78 | + } |
| 79 | + return false; |
| 80 | + } |
| 81 | + |
| 82 | + @Override |
| 83 | + public void clear() { |
| 84 | + this.head.next = null; |
| 85 | + this.last = null; |
| 86 | + |
| 87 | + this.size = 0; |
| 88 | + } |
| 89 | + |
| 90 | + @Override |
| 91 | + public T get(int index) { |
| 92 | + return getNode(index).data; |
| 93 | + } |
| 94 | + |
| 95 | + @Override |
| 96 | + public T set(int index, T element) { |
| 97 | + Node<T> node = getNode(index); |
| 98 | + node.data = element; |
| 99 | + return element; |
| 100 | + } |
| 101 | + |
| 102 | + @Override |
| 103 | + public void add(int index, T element) { |
| 104 | + if (index <= 0 || index >= this.size) { |
| 105 | + throw new IndexOutOfBoundsException(); |
| 106 | + } |
| 107 | + Node<T> node = this.head; |
| 108 | + for (int i = 0; i <= index; i++) { |
| 109 | + node = node.next; |
| 110 | + } |
| 111 | + Node<T> pre = node.pre; |
| 112 | + Node<T> newNode = new Node<>(element); |
| 113 | + pre.next = newNode; |
| 114 | + newNode.pre = pre; |
| 115 | + newNode.next = node; |
| 116 | + node.pre = newNode; |
| 117 | + |
| 118 | + this.size++; |
| 119 | + } |
| 120 | + |
| 121 | + @Override |
| 122 | + public T remove(int index) { |
| 123 | + Node<T> node = getNode(index); |
| 124 | + Node<T> pre = node.pre; |
| 125 | + Node<T> next = node.next; |
| 126 | + pre.next = next; |
| 127 | + if (next != null) { |
| 128 | + next.pre = pre; |
| 129 | + } |
| 130 | + |
| 131 | + this.size--; |
| 132 | + return node.data; |
| 133 | + } |
| 134 | + |
| 135 | + @Override |
| 136 | + public int indexOf(T o) { |
| 137 | + Node node = this.head; |
| 138 | + int index = 0; |
| 139 | + while (node.next != null) { |
| 140 | + node = node.next; |
| 141 | + if (Objects.equals(node.data, o)) { |
| 142 | + return index; |
| 143 | + } |
| 144 | + index++; |
| 145 | + } |
| 146 | + return -1; |
| 147 | + } |
| 148 | + |
| 149 | + @Override |
| 150 | + public KIterator<T> iterator() { |
| 151 | + throw new UnsupportedOperationException("方法未实现"); |
| 152 | + } |
| 153 | + |
| 154 | + private Node<T> getNode(int index) { |
| 155 | + if (index < 0 || index >= size) { |
| 156 | + throw new IndexOutOfBoundsException(); |
| 157 | + } |
| 158 | + |
| 159 | + Node<T> node = this.head; |
| 160 | + for (int i = 0; i <= index; i++) { |
| 161 | + node = node.next; |
| 162 | + } |
| 163 | + return node; |
| 164 | + } |
| 165 | + |
| 166 | + private static class Node<T> { |
| 167 | + T data; |
| 168 | + Node<T> pre; |
| 169 | + Node<T> next; |
| 170 | + |
| 171 | + Node(T data) { |
| 172 | + this.data = data; |
| 173 | + } |
| 174 | + } |
| 175 | +} |
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