70 lines
2.0 KiB
Java
70 lines
2.0 KiB
Java
// collectiontopics/SimpleDeques.java
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// (c)2021 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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// Very basic test of Deques
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import java.util.*;
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import java.util.concurrent.*;
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import java.util.function.*;
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class CountString implements Supplier<String> {
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private int n = 0;
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CountString() {}
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CountString(int start) { n = start; }
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@Override public String get() {
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return Integer.toString(n++);
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}
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}
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public class SimpleDeques {
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static void test(Deque<String> deque) {
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CountString s1 = new CountString(),
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s2 = new CountString(20);
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for(int n = 0; n < 8; n++) {
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deque.offerFirst(s1.get());
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deque.offerLast(s2.get()); // Same as offer()
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}
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System.out.println(deque);
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String result = "";
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while(deque.size() > 0) {
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System.out.print(deque.peekFirst() + " ");
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result += deque.pollFirst() + " ";
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System.out.print(deque.peekLast() + " ");
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result += deque.pollLast() + " ";
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}
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System.out.println("\n" + result);
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}
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public static void main(String[] args) {
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int count = 10;
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System.out.println("LinkedList");
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test(new LinkedList<>());
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System.out.println("ArrayDeque");
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test(new ArrayDeque<>());
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System.out.println("LinkedBlockingDeque");
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test(new LinkedBlockingDeque<>(count));
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System.out.println("ConcurrentLinkedDeque");
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test(new ConcurrentLinkedDeque<>());
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}
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}
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/* Output:
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LinkedList
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[7, 6, 5, 4, 3, 2, 1, 0, 20, 21, 22, 23, 24, 25, 26,
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27]
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7 27 6 26 5 25 4 24 3 23 2 22 1 21 0 20
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7 27 6 26 5 25 4 24 3 23 2 22 1 21 0 20
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ArrayDeque
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[7, 6, 5, 4, 3, 2, 1, 0, 20, 21, 22, 23, 24, 25, 26,
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27]
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7 27 6 26 5 25 4 24 3 23 2 22 1 21 0 20
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7 27 6 26 5 25 4 24 3 23 2 22 1 21 0 20
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LinkedBlockingDeque
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[4, 3, 2, 1, 0, 20, 21, 22, 23, 24]
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4 24 3 23 2 22 1 21 0 20
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4 24 3 23 2 22 1 21 0 20
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ConcurrentLinkedDeque
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[7, 6, 5, 4, 3, 2, 1, 0, 20, 21, 22, 23, 24, 25, 26,
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27]
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7 27 6 26 5 25 4 24 3 23 2 22 1 21 0 20
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7 27 6 26 5 25 4 24 3 23 2 22 1 21 0 20
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*/
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