Lucy's Note of Coding

import static utitled.SingleLinkedList.mergeLinkedListByOrder;
import static utitled.SingleLinkedList.showAllNodes;

public class Test {

  public static void main(String[] args) {

    // create first SingleLinkedList
    SingleLinkedList singleLinkedList1 = new SingleLinkedList();
    singleLinkedList1.addByOrder(new NumberNode(23));
    singleLinkedList1.addByOrder(new NumberNode(1));
    singleLinkedList1.addByOrder(new NumberNode(5));
    singleLinkedList1.addByOrder(new NumberNode(49));

    // create second SingleLinkedList
    SingleLinkedList singleLinkedList2 = new SingleLinkedList();
    singleLinkedList2.addByOrder(new NumberNode(4));
    singleLinkedList2.addByOrder(new NumberNode(3));
    singleLinkedList2.addByOrder(new NumberNode(17));
    singleLinkedList2.addByOrder(new NumberNode(89));
    singleLinkedList2.addByOrder(new NumberNode(99));
    singleLinkedList2.addByOrder(new NumberNode(111));
    singleLinkedList2.addByOrder(new NumberNode(133));
    singleLinkedList2.addByOrder(new NumberNode(125));
    singleLinkedList2.addByOrder(new NumberNode(112));
    singleLinkedList2.addByOrder(new NumberNode(114));

    NumberNode returnHead = mergeLinkedListByOrder(singleLinkedList1.getHead(), singleLinkedList2.getHead());
    showAllNodes(returnHead);

  }
}

/**
 * 新建類別(SingleLinkedList)模擬單向鏈接串列
 */
class SingleLinkedList {

  // step1:new a head node, without data
  private NumberNode head = new NumberNode(0);

  public NumberNode getHead() {
    return head;
  }


  public void addByOrder(NumberNode numberNode) {
    NumberNode temp = head;

    while (true) {
      if (temp.getNextNode() == null
          || temp.getNextNode().getNumberNo()
          > numberNode.getNumberNo()) {// headNo:1 numberNode:2 headNextNode:4
        // exchange position between three nodes
        numberNode.setNextNode(temp.getNextNode());
        temp.setNextNode(numberNode);
        break;
      } else if (temp.getNextNode().getNumberNo() == numberNode.getNumberNo()) {
        System.out.printf("此數字編號：%d已存在，無法新增此節點\n", numberNode.getNumberNo());
        break;
      }
      temp = temp.getNextNode();
    }
  }

  public static void showAllNodes(NumberNode head) {
    // to check this LinkedList has node or not? but not to change head node
    NumberNode temp = head.getNextNode();
    while (true) {
      if (temp == null) {
        // already moved to the end of LinkedList then return function
        return;
      }
      System.out.println(temp);
      temp = temp.getNextNode();
    }
  }

  /**
   *
   * @param head1
   * @param head2
   * @return head 最終合併至的頭節點
   */
  public static NumberNode mergeLinkedListByOrder(NumberNode head1, NumberNode head2) {
    if (head1.getNextNode() == null || head2.getNextNode() == null) {
      // any LinkedList without nodes, it's none sense to merge
      if (head1.getNextNode() != null) {
        return head1;
      } else if (head2.getNextNode() != null) {
        return head2;
      }
    }
    // merge
    // keep headNode depends on smaller first node
    NumberNode head = head1.getNextNode().getNumberNo() < head2.getNextNode().getNumberNo() ? head1 : head2;
    NumberNode returnHead = head;
    NumberNode cur1 = head1.getNextNode();
    NumberNode cur2 = head2.getNextNode();
    while (cur1 != null && cur2 != null) {
      if (cur1.getNumberNo() < cur2.getNumberNo()) {
        // take smaller node to head
        head.setNextNode(cur1);
        //move to next node
        cur1 = cur1.getNextNode();
      } else {
        // take smaller node to head
        head.setNextNode(cur2);
        // move to next node
        cur2 = cur2.getNextNode();
      }
      // move to next node
      head = head.getNextNode();
    }
    NumberNode next = null;
    if (cur1 != null) {
      next = cur1.getNextNode();
      head.setNextNode(cur1);
      head.getNextNode().setNextNode(next);
    } else if  (cur2 != null) {
      next = cur2.getNextNode();
      head.setNextNode(cur2);
      head.getNextNode().setNextNode(next);
    }
    return returnHead;
  }
}

/**
 * 新建類別(NumberNode)模擬LinkedList的節點
 */
class NumberNode {

  private int numberNo;
  private NumberNode nextNode;

  // constructor
  public NumberNode(int no) {
    this.numberNo = no;
  }

  public int getNumberNo() {
    return numberNo;
  }

  public void setNumberNo(int numberNo) {
    this.numberNo = numberNo;
  }

  public NumberNode getNextNode() {
    return nextNode;
  }

  public void setNextNode(NumberNode nextNode) {
    this.nextNode = nextNode;
  }

  @Override
  public String toString() {
    final StringBuilder sb = new StringBuilder("NumberNode{");
    sb.append("numberNo=").append(numberNo);
    sb.append(", nextNode=").append(nextNode);
    sb.append('}');
    return sb.toString();
  }
}

如有敘述錯誤，還請不吝嗇留言指教，thanks!