class Solution(object):
def mergeKLists(self, lists):
"""
:type lists: List[ListNode]
:rtype: ListNode
"""
currHeap = []
head, l = None, None
for li in lists:
if li is not None:
heappush(currHeap, (li.val, li))
while currHeap:
val, node = heappop(currHeap)
newNode = ListNode(val)
if node.next is not None:
heappush(currHeap, (node.next.val, node.next))
if not head:
head, l = newNode, newNode
else:
l.next = newNode
l = l.next
return head
if __name__ == '__main__':
sol = Solution()
l1 = get_list([1, 2, 3])
l2 = get_list([4, 5])
l3 = get_list([])
lists = [l1, l2, l3]
result = sol.mergeKLists(lists)
print(result)
remove.counter = -1
else:
remove(head, st.next, n)
remove.counter += 1
if remove.counter == n - 1:
remove.nextNode = st
if remove.counter == n + 1:
st.next = remove.nextNode
if st == head and remove.counter == n:
return False
return True
class Solution(object):
def removeNthFromEnd(self, head, n):
"""
:type head: ListNode
:type n: int
:rtype: ListNode
"""
st = head
if not remove(head, st, n):
return head.next
else:
return head
if __name__ == '__main__':
data = [2, 3, 4, 5]
head = get_list(data)
sol = Solution()
result = sol.removeNthFromEnd(head, 4)
print(result)
"""
:type l1: ListNode
:type l2: ListNode
:rtype: ListNode
"""
val, addition = 0, 0
l, head = None, None
while l1 is not None or l2 is not None or addition:
v1 = l1.val if l1 is not None else 0
v2 = l2.val if l2 is not None else 0
val = v1 + v2 + addition
addition = val // 10
if l is None:
l = ListNode(val % 10)
head = l
else:
l.next = ListNode(val % 10)
l = l.next
l1 = l1.next if l1 is not None else None
l2 = l2.next if l2 is not None else None
return head
if __name__ == '__main__':
l1 = get_list([4, 3, 2])
l2 = get_list([9, 1])
sol = Solution()
head = sol.addTwoNumbers(l1, l2)
while head is not None:
print(head.val)
head = head.next
def swapPairs(self, head):
"""
:type head: ListNode
:rtype: ListNode
"""
if head is None:
return head
st1 = head
st2 = head.next
previousNode = None
while st1 is not None and st2 is not None:
if previousNode is None:
st1.next = st2.next
st2.next = st1
head = st2
else:
st1.next = st2.next
st2.next = st1
previousNode.next = st2
previousNode = st1
st1 = st1.next
st2 = st1.next if st1 is not None else None
return head
if __name__ == "__main__":
sol = Solution()
l = get_list([1, 3, 2, 1])
result = sol.swapPairs(l)
print(result)
