68 lines
1.6 KiB
Java
68 lines
1.6 KiB
Java
package data;
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import java.util.List;
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import java.util.Spliterator;
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import java.util.function.Consumer;
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public class StudentSpliterator implements Spliterator<Student> {
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private final List<Student> studentList;
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private int endIndex;
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private int startIndex;
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public StudentSpliterator(List<Student> studentList) {
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this(studentList, 0, studentList.size());
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}
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private StudentSpliterator(List<Student> studentList, int startIndex, int endIndex) {
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this.studentList = studentList;
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this.startIndex = startIndex;
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this.endIndex = endIndex;
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}
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@Override
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public boolean tryAdvance(Consumer<? super Student> action) {
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if (getSize() > 0) {
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action.accept(studentList.get(startIndex));
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startIndex++;
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return true;
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}
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return false;
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}
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@Override
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public Spliterator<Student> trySplit() {
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if (getSize() == 1) {
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return null;
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}
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int newStartIndex;
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int newEndIndex = endIndex;
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if (getSize() % 2 == 0) {
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newStartIndex = startIndex + getSize() / 2;
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this.endIndex -= getSize() / 2;
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} else {
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newStartIndex = startIndex + getSize() / 2 + 1;
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this.endIndex -= getSize() / 2;
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}
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return new StudentSpliterator(studentList, newStartIndex, newEndIndex);
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}
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private int getSize() {
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return endIndex - startIndex;
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}
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@Override
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public long estimateSize() {
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return studentList.size();
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}
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@Override
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public int characteristics() {
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return NONNULL;
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}
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}
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