题解 | #反转链表#

class Solution:
    def ReverseList(self, head: ListNode) -> ListNode:
        prev = None
        current = head
        
        while current:
            next_node = current.next  # 暂存下一个节点
            current.next = prev       # 反转当前节点的指针
            prev = current            # 将 prev 前移
            current = next_node       # 将 current 前移
        
        return prev  # prev 是新的头节点