該題為劍指offer面試題26

• 
  熱度指數：70797  時間限制：1秒  空間限制：32768K

package go.jacob.day430;

public class Demo1 {
	public RandomListNode Clone(RandomListNode pHead) {
		createDoubleNode(pHead);

		connectRandomNode(pHead);

		RandomListNode newHead = ReconnectNodes(pHead);
		return newHead;

	}

	/*
	 * 複製節點，把新建的節點A‘連線在原節點A後
	 */
	private void createDoubleNode(RandomListNode pHead) {
		RandomListNode tmpNode = pHead;
		while (tmpNode != null) {
			RandomListNode node = new RandomListNode(tmpNode.label);
			node.next = tmpNode.next;
			tmpNode.next = node;
			tmpNode = node.next;
		}
	}

	/*
	 * 連結random節點，eg. 在原連結串列中A的random是B，那麼在新連結串列中，A’連結B‘
	 */
	private void connectRandomNode(RandomListNode pHead) {
		RandomListNode tmpNode = pHead;
		while (tmpNode != null) {
			if (tmpNode.random != null) {
				RandomListNode node = tmpNode.next;
				node.random = tmpNode.random.next;
				tmpNode = node.next;
			} else {
				tmpNode = tmpNode.next.next;
			}
		}
	}

	/*
	 * 把兩個相連的連結串列拆分成兩個
	 */
	private RandomListNode ReconnectNodes(RandomListNode pHead) {
		if (pHead == null)
			return null;
		RandomListNode tmpNode = pHead;
		RandomListNode newHead = pHead.next;

		while (tmpNode != null) {
			RandomListNode node = tmpNode.next;
			tmpNode.next = node.next;
			if (node.next != null)
				node.next = node.next.next;
			else
				node.next = null;
			tmpNode = tmpNode.next;
		}

		return newHead;
	}

	// 節點類
	public class RandomListNode {
		int label;
		RandomListNode next = null;
		RandomListNode random = null;

		RandomListNode(int label) {
			this.label = label;
		}
	}
}