95 lines
2.2 KiB
Java
95 lines
2.2 KiB
Java
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class AssociationList<Key, Value> {
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class Node {
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private Key key;
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private Value value;
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private Node next;
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public Node(Key key, Value value, Node next) {
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this.key = key;
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this.value = value;
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this.next = next;
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}
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}
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private Node head;
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public AssociationList() {
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head = new Node(null, null, null);
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}
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public Value get(Key key) {
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Node search = head.next;
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while (search != null) {
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if (search.key.equals(key)) {
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return search.value;
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}
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search = search.next;
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}
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throw new IllegalArgumentException("Key not found.");
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}
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public boolean isEmpty() {
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return head.next == null;
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}
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public void put(Key key, Value value) {
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if (key == null)
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throw new IllegalArgumentException("Key is null.");
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Node search = head.next;
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while (search != null) {
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if (search.key.equals(key)) {
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search.value = value;
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return;
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}
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search = search.next;
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}
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Node newNode = new Node(key, value, head.next);
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head.next = newNode;
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}
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public void remove(Key key) {
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Node search = head;
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while (search.next != null) {
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if (search.next.key.equals(key)) {
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search.next = search.next.next;
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return;
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}
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search = search.next;
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}
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}
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}
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class SmallMediumLarge
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{
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public static void main(String [] args)
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{
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AssociationList<String, Integer> a = new AssociationList<String, Integer>();
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a.put("small", 0);
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a.put("medium", 1);
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a.put("large", 2);
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System.out.println(a.get("small")); // 0
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System.out.println(a.get("medium")); // 1
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System.out.println(a.get("large")); // 2
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a.put("large", 1000);
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System.out.println(a.get("small")); // 0
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System.out.println(a.get("medium")); // 1
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System.out.println(a.get("large")); // 1000
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a.remove("large");
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System.out.println(a.get("small")); // 0
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System.out.println(a.get("medium")); // 1
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System.out.println(a.get("large")); // Throw an exception.
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}
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}
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/*
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0
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1
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2
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0
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1
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1000
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0
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1
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Exception in thread "main" java.lang.IllegalArgumentException: Key not found.
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at AssociationList.get(SmallMediumLarge.java:24)
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at SmallMediumLarge.main(SmallMediumLarge.java:79)
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*/
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