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import java.util.ArrayList;
import java.util.List;
public class Main {
public static void main(String[] args) {
Node firstNode = createNode(4);
System.out.println("origin:" + firstNode);
resortNode(firstNode);
System.out.println("resorted:" + firstNode);
firstNode = createNode(5);
System.out.println("origin:" + firstNode);
resortNode(firstNode);
System.out.println("resorted:" + firstNode);
}
private static void resortNode(Node node) {
List<Node> list = new ArrayList<>();
while (node != null) {
list.add(node);
node = node.next;
}
for (int i = 0; i < list.size(); i++) {
Node head = list.get(i);
Node tail = list.get(list.size() - i - 1);
if (head == tail) {
head.next = null;
break;
}
if (head.next == tail) {
tail.next = null;
break;
}
tail.next = head.next;
head.next = tail;
}
}
private static Node createNode(int num) {
Node tail = new Node(num, null);
for (int i = num - 1; i > 0; i--) {
tail = new Node(i, tail);
}
return tail;
}
static class Node {
public Node(int value, Node next) {
this.value = value;
this.next = next;
}
int value;
Node next;
@Override
public String toString() {
return value + (next == null ? "" : ("->" + next));
}
}
}
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