java鏈表反轉代碼怎么寫

以下是Java中鏈表反轉的示例代碼：

public class ListNode {
    int val;
    ListNode next;

    ListNode(int val) {
        this.val = val;
    }
}

public class LinkedListReverse {
    public static ListNode reverseList(ListNode head) {
        ListNode prev = null;
        ListNode current = head;
        ListNode next = null;

        while (current != null) {
            next = current.next;
            current.next = prev;
            prev = current;
            current = next;
        }

        return prev;
    }

    public static void main(String[] args) {
        ListNode head = new ListNode(1);
        head.next = new ListNode(2);
        head.next.next = new ListNode(3);
        head.next.next.next = new ListNode(4);
        head.next.next.next.next = new ListNode(5);

        ListNode reversedHead = reverseList(head);

        System.out.print("Reversed List: ");
        while (reversedHead != null) {
            System.out.print(reversedHead.val + " ");
            reversedHead = reversedHead.next;
        }
    }
}

運行以上代碼，將會輸出反轉后的鏈表：

Reversed List: 5 4 3 2 1

在反轉鏈表的代碼中，我們使用了三個指針prev、current和next。初始時，prev為null，current為頭節點head，next為null。在每一次循環中，我們將current的next指針指向prev，然后依次向后移動prev、current和next指針。最終，prev指針將指向反轉后的鏈表頭節點，我們將其返回即可。