merge_k_sorted_lists.py

"""
You are given an array of k linked-lists lists, each linked-list is sorted in ascending order.

Merge all the linked-lists into one sorted linked-list and return it"""


def merge_k_lists(lists):
    """
    :type lists: List[ListNode]
    :rtype: ListNode
    """
    if not lists:
        return None
    dummy = ListNode(0)
    curr = dummy
    while lists:
        min_node = min(lists, key=lambda x: x.val)
        curr.next = min_node
        curr = curr.next
        lists.remove(min_node)
        if min_node.next:
            min_node = min_node.next
        else:
            break
    return dummy.next