Input: 1->2->3->4->5->NULL, m = 2, n = 4
Output: 1->4->3->2->5->NULL
:param head:
:param m:
:param n:
:return:
"""
if not head or m == n:
return head
p = dummy = ListNode(0)
dummy.next = head
for i in range(m - 1):
p = p.next
tail = p.next
for i in range(n - m):
tmp = p.next
p.next = tail.next
tail.next = tail.next.next
p.next.next = tmp
return dummy.next
if __name__ == '__main__':
nums = [1, 2, 3, 4, 5]
ln = create_listnode(nums)
show_listnode(ln)
s = Solution()
ln = s.reverseBetween(ln, 1, 5)
show_listnode(ln)
tail = ListNode(0)
while stack1 or stack2:
if stack1:
s += stack1.pop().val
if stack2:
s += stack2.pop().val
tail.val = int(s % 10)
tmp = ListNode(int(s // 10))
tmp.next = tail
tail = tmp
s /= 10
return tail if tail.val != 0 else tail.next
if __name__ == '__main__':
"""
正常 9, 0
进一位 1, 9
进两位 22, 78
进N位 3334, 6666
"""
s = Solution()
nums1 = [2, 2]
nums2 = [7, 8]
ln1 = create_listnode(nums1)
ln2 = create_listnode(nums2)
show_listnode(ln1)
show_listnode(ln2)
show_listnode(s.addTwoNumbers2(ln1, ln2))
def removeElements3(self, head: ListNode, val: int) -> ListNode:
"""
recursive
:param head:
:param val:
:return:
"""
if not head:
return head
head.next = self.removeElements2(head.next, val)
return head if head.val != val else head.next
if __name__ == '__main__':
s = Solution()
nums = [1, 2, 3]
val = 2
list_nodes = create_listnode(nums)
show_listnode(list_nodes)
list_nodes = s.removeElements1(list_nodes, val)
show_listnode(list_nodes)
list_nodes = create_listnode(nums)
list_nodes = s.removeElements2(list_nodes, val)
show_listnode(list_nodes)
list_nodes = create_listnode(nums)
list_nodes = s.removeElements3(list_nodes, val)
show_listnode(list_nodes)
from DataStructure.ListNode import ListNode, create_listnode, show_listnode
class Solution:
def insertionSortList(self, head: ListNode) -> ListNode:
p = dummy = ListNode(0)
curr = dummy.next = head
while curr and curr.next:
val = curr.next.val
if curr.val <= val:
curr = curr.next
continue
if p.next.val > val:
p = dummy
while p.next.val <= val:
p = p.next
tmp = curr.next
curr.next = tmp.next
tmp.next = p.next # 不是 tmp.next = curr e.g. [4, 4, 3, 2, 1]
p.next = tmp
return dummy.next
if __name__ == '__main__':
s = Solution()
nums = [4, 3, 2, 1]
list_node = create_listnode(nums)
show_listnode(list_node)
ans = s.insertionSortList(list_node)
show_listnode(ans)
