57 lines
1.4 KiB
Java
57 lines
1.4 KiB
Java
// collectiontopics/ToDoList.java
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// (c)2017 MindView LLC: see Copyright.txt
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// We make no guarantees that this code is fit for any purpose.
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// Visit http://OnJava8.com for more book information.
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// A more complex use of PriorityQueue
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import java.util.*;
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class ToDoItem implements Comparable<ToDoItem> {
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private char primary;
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private int secondary;
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private String item;
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ToDoItem(String td, char pri, int sec) {
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primary = pri;
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secondary = sec;
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item = td;
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}
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@Override
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public int compareTo(ToDoItem arg) {
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if(primary > arg.primary)
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return +1;
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if(primary == arg.primary)
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if(secondary > arg.secondary)
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return +1;
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else if(secondary == arg.secondary)
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return 0;
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return -1;
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}
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@Override
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public String toString() {
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return Character.toString(primary) +
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secondary + ": " + item;
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}
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}
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class ToDoList {
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public static void main(String[] args) {
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PriorityQueue<ToDoItem> toDo =
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new PriorityQueue<>();
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toDo.add(new ToDoItem("Empty trash", 'C', 4));
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toDo.add(new ToDoItem("Feed dog", 'A', 2));
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toDo.add(new ToDoItem("Feed bird", 'B', 7));
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toDo.add(new ToDoItem("Mow lawn", 'C', 3));
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toDo.add(new ToDoItem("Water lawn", 'A', 1));
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toDo.add(new ToDoItem("Feed cat", 'B', 1));
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while(!toDo.isEmpty())
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System.out.println(toDo.remove());
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}
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}
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/* Output:
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A1: Water lawn
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A2: Feed dog
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B1: Feed cat
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B7: Feed bird
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C3: Mow lawn
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C4: Empty trash
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*/
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