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| 9. 22. 1. NavigableSet接口 |
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The NavigableSet interface is a subinterface of SortedSet that provides methods for searching for elements. |
java.util.TreeSet is an implementation of NavigableSet. |
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import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import java.util.NavigableSet;
import java.util.TreeSet;
public class NavigableSetDemo {
public static void main(String[] args) {
List<Integer> list = Arrays.asList(3, 2, 4, 1, 5);
NavigableSet<Integer> ns = new TreeSet<Integer>(list);
System.out.println("Ascending order (default): " + ns);
Iterator<Integer> descendingIterator = ns.descendingIterator();
StringBuilder sb = new StringBuilder("Descending order: ");
while (descendingIterator.hasNext()) {
int m = descendingIterator.next();
sb.append(m + " ");
}
System.out.println(sb);
int greatest = ns.lower(3);
System.out.println("Lower of 3 = " + greatest);
int smallest = ns.higher(3);
System.out.println("Higher of 3 = " + smallest);
}
}
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Ascending order (default): [1, 2, 3, 4, 5]
Descending order: 5 4 3 2 1
Lower of 3 = 2
Higher of 3 = 4 |
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