在python中重新排列链表

class ListNode:
    def __init__(self, val=0, next=None):
        self.val = val
        self.next = next

def oddEvenList(head):
    if not head or not head.next:
        return head
    
    odd = head
    even = head.next
    even_head = even
    
    while even and even.next:
        odd.next = even.next
        odd = odd.next
        even.next = odd.next
        even = even.next
    
    odd.next = even_head
    return head

# 辅助函数：打印链表
def printList(head):
    current = head
    while current:
        print(current.val, end=" -> ")
        current = current.next
    print("None")

# 创建链表 1 -> 2 -> 3 -> 4 -> 5
head = ListNode(1, ListNode(2, ListNode(3, ListNode(4, ListNode(5)))))
print("Original list:")
printList(head)

# 重新排列链表
rearranged_head = oddEvenList(head)
print("Rearranged list:")
printList(rearranged_head)