如何在不使用循环的情况下将数组递归转换为链表？ 对于 python

Question

def array_to_list_recursive(data):
    i = 0
    if len(data) == 0:
        return None
    else:
        head = ListNode(data[i])
        if i <= len(data):
            i += 1
        return head

This is what I have right now but it only prints out the first node. Thanks in advance.

Answer 1

You can try something like

class Node:
    def __init__(self, val, next=None):
        self.val = val
        self.next = next
    def print_node(self):
        current = self
        print(current.val, '-->', end='')
        current = current.next
        while(current):
            print(current.val, '-->', end='')
            current = current.next
        
l = [1, 5, 3, 7]
assert(len(l) > 0)

def produce_ll(l, head=None, current=None, index=0):
    if(index > len(l)-1):
        return head
    
    if(head == None):
        head = Node(l[index])
        current = head
        return produce_ll(l, head, current, index+1)
    
    next_node = Node(l[index])
    current.next = next_node
    current = next_node
    index += 1
    return produce_ll(l, head, current, index)

head = produce_ll(l)
print(head.print_node())

1 -->5 -->3 -->7 -->None