58 lines
1.6 KiB
Java
58 lines
1.6 KiB
Java
// collectionsindepth/ToDoList.java
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// (c)2016 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://mindviewinc.com/Books/OnJava/ 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 ToDoList extends PriorityQueue<ToDoList.ToDoItem> {
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static 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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public 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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public void add(String td, char pri, int sec) {
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super.add(new ToDoItem(td, pri, sec));
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}
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public static void main(String[] args) {
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ToDoList toDoList = new ToDoList();
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toDoList.add("Empty trash", 'C', 4);
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toDoList.add("Feed dog", 'A', 2);
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toDoList.add("Feed bird", 'B', 7);
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toDoList.add("Mow lawn", 'C', 3);
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toDoList.add("Water lawn", 'A', 1);
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toDoList.add("Feed cat", 'B', 1);
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while(!toDoList.isEmpty())
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System.out.println(toDoList.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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