鏈表1：反轉單向鏈表，雙向鏈表

反轉單向鏈表
思想：有好幾種方法：這裏採用的是創建一個新的鏈表來存放新產生的鏈表，把原鏈表的表頭節點依次接到新的鏈表中

代碼：

public static class Node {   //定義一個Node節點類
		public int value;
		public Node next;

		public Node(int data) {
			this.value = data;
		}
	}
         //這裏採用的是建立一個新的鏈表來存放倒序產生的鏈表
	public static Node reverseList(Node head) {  
		Node pre = null;   // 定義兩個空節點
		Node next = null;     
		while (head != null) {  //head是每個要接在鏈表的開頭的那個節點
			next = head.next;   //要改變的節點
			head.next = pre;
			pre = head;
			head = next;
		}
		return pre;  // 返回倒序的鏈表
	}

反轉雙向鏈表
思想：跟單向鏈表的反轉相似，但是這裏要注意它有一個前驅指針，大致思想跟單向的差不多，具體看代碼，這裏再加上測試代碼等
代碼：

public static class DoubleNode {
		public int value;
		public DoubleNode last;//前驅
		public DoubleNode next;//後繼

		public DoubleNode(int data) {
			this.value = data;
		}
	}

	public static DoubleNode reverseList(DoubleNode head) {
		DoubleNode pre = null;
		DoubleNode next = null;
		while (head != null) {
			next = head.next;
			head.next = pre;
			head.last = next;
			pre = head;
			head = next;
		}
		return pre;
	}
	public static void printLinkedList(Node head) {
		System.out.print("Linked List: ");
		while (head != null) {
			System.out.print(head.value + " ");
			head = head.next;
		}
		System.out.println();
	}

	public static void printDoubleLinkedList(DoubleNode head) {
		System.out.print("Double Linked List: ");
		DoubleNode end = null;
		while (head != null) {
			System.out.print(head.value + " ");
			end = head;
			head = head.next;
		}
		System.out.print("| ");
		while (end != null) {
			System.out.print(end.value + " ");
			end = end.last;
		}
		System.out.println();
	}

	public static void main(String[] args) {
		Node head1 = new Node(1);
		head1.next = new Node(2);
		head1.next.next = new Node(3);
		printLinkedList(head1);//上面三行代碼表示構建了一個head1鏈表
		head1 = reverseList(head1);
		printLinkedList(head1);

		DoubleNode head2 = new DoubleNode(1);
		head2.next = new DoubleNode(2);
		head2.next.last = head2;
		head2.next.next = new DoubleNode(3);
		head2.next.next.last = head2.next;
		head2.next.next.next = new DoubleNode(4);
		head2.next.next.next.last = head2.next.next;
		printDoubleLinkedList(head2);
		printDoubleLinkedList(reverseList(head2));

	}

還有其他的方法，可以參考一下；鏈接：點擊