使用Python将新值插入SortedLinked List？

Question

我实现了以下代码，它可以工作，但它在链表末尾添加了新值，例如 [1,2,3,6]，值 4 结果是 [1,2,3,6,4] 这是错误的 正确的结果是[1,2,3,4,6]

# Singly-linked lists are already defined with this interface:
class ListNode(object):
    def __init__(self, x):
        self.value = x
        self.next = None

def insertValueIntoSortedLinkedList(head, valuetoInsert):

    currentNode = head

    while currentNode is not None:
        if currentNode.next is None:
            currentNode.next = ListNode(valuetoInsert)
            return head
        currentNode = currentNode.next

我的问题如何修改 insertValueIntoSortedLinkedList 函数 谢谢

Answer 1

我对@9​​87654321@ 做了一些更改。基本上，错误是您不比较要插入的值是否小于当前值（因此您总是将新值插入到结尾）。

# Singly-linked lists are already defined with this interface:
class ListNode(object):
    def __init__(self, x):
        self.value = x
        self.next = None

def insertValueIntoSortedLinkedList(head, valuetoInsert):
    currentNode = head
    while True:
        # is current value greater than value we are going to insert?
        if currentNode.value > valuetoInsert:
            # yes, create new node with old value
            next_node = ListNode(currentNode.value)
            next_node.next = currentNode.next

            # replace current value with new value (which is lower than old value)
            currentNode.value = valuetoInsert

            # set next node to new node we created previously (with old value)
            currentNode.next = next_node
            # we are done, return
            return

        # we are at the end, so break from while-loop
        if currentNode.next is None:
            break

        currentNode = currentNode.next

    # the valuetoInsert is greater than all values so far, so insert it to the end
    currentNode.next = ListNode(valuetoInsert)

def print_list(head):
    """ Helper method to print the list """
    currentNode = head

    while currentNode is not None:
        print(currentNode.value)
        currentNode = currentNode.next

l = ListNode(1)
insertValueIntoSortedLinkedList(l, 2)
insertValueIntoSortedLinkedList(l, 3)
insertValueIntoSortedLinkedList(l, 6)

insertValueIntoSortedLinkedList(l, 4)  # this inserts value before 6

print_list(l)

打印：

1
2
3
4
6