手写单链表，并实现元素逆置

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public class SinglyLinkedList<T> {
    // 一个空的头节点
    private final Node head = new Node(null);
    private Node tail = head;

    @SafeVarargs
    public final void addAll(T... data) {
        if (data == null) return;
        for (T datum : data) {
            tail.next = new Node(datum);
            tail = tail.next;
        }
    }

    public void reverse() {
        Node index = head.next, pre = head;
        if (index == null || index.next == null) return;

        Node des = index.next, newTail = index;

        do {
            index.next = pre;
            pre = index;
            index = des;
            if (index != null)
                des = index.next;
        } while (index != null);

        tail = newTail;
        tail.next = null;
        head.next = pre;
    }

    @Override
    public String toString() {
        Node i = head.next;
        StringBuilder buffer = new StringBuilder();
        while (i != null) {
            buffer.append(" ").append(i.data).append(" ");
            i = i.next;
        }
        return buffer.toString();
    }

    @Data
    @NoArgsConstructor
    @AllArgsConstructor
    private class Node {
        private T data;
        private Node next;

        public Node(T data) {
            this.data = data;
        }
    }
}

单元测试：

class SinglyLinkedListTest {

    @Test
    void reverse() {
        SinglyLinkedList<Integer> list = new SinglyLinkedList<>();
        list.addAll(5, 4, 3, 2, 1);
        list.reverse();
        System.out.println(list.toString());
    }
}

输出：

 1  2  3  4  5 

手写单链表，并实现元素逆置

标签：system   ide   vat   head   lis   turn   override   ring   rev   

原文地址：https://www.cnblogs.com/xch-jiang/p/14386306.html