def reverseList1(self, head: ListNode) -> ListNode:
if not head:
return []
l = []
while head:
l.append(head)
head = head.next
root = l.pop()
head = root
while l:
head.next = l.pop()
head = head.next
head.next = None
return root
def insertionSortList1(self, head: ListNode) -> ListNode:
if not head:
return head
cur, nxt = head, head.next
dummy = ListNode(float('-inf'))
dummy.next = head
while nxt:
if nxt.val >= cur.val:
cur, nxt = nxt, nxt.next
else:
cur.next = nxt.next
pre1, pre2 = dummy, dummy.next
while nxt.val > pre2.val:
pre1, pre2 = pre2, pre2.next
pre1.next = nxt
nxt.next = pre2
nxt = cur.next
return dummy.next
def partition(self, head: ListNode, x: int) -> ListNode:
"""
分成左中右
"""
sh = None
st = None
bh = None
bt = None
eh = None
et = None
while head:
next = head.next
head.next = None
if head.val < x:
if not sh:
sh = head
st = head
else:
st.next = head
st = head
elif head.val == x:
if not eh:
eh = head
et = head
else:
et.next = head
et = head
else:
if not bh:
bh = head
bt = head
else:
bt.next = head
bt = head
head = next
if st:
st.next = eh
et = st if not et else et # 谁连大于区域的头谁变成et
if et:
et.next = bh
return sh if sh else (eh if eh else bh)
while head:
l.append(head)
head = head.next
root = l.pop()
head = root
while l:
head.next = l.pop()
head = head.next
head.next = None
return root
def reverseList(self, head: ListNode) -> ListNode:
if not head:
return []
pre = None
cur = head
while cur:
temp = cur.next
cur.next = pre
pre = cur
cur = temp
return pre
if __name__ == "__main__":
a = Solution()
l = ListNode([1, 2, 3, 4, 5])
# q = a.reverseList(l)
print(l)
# print(q)
from 链表类 import ListNode
from 反转链表 import Solution as S
class Solution:
def isPalindrome(self, head: ListNode) -> bool:
if not head:
return True
slow = fast = head
while fast and fast.next:
slow = slow.next
fast = fast.next.next
# 出循环时fast是最后一个节点，slow是中间节点或前半段的最后一个节点
fast = S().reverseList(slow)
slow = head
# print("slow",slow)
# print("fast",fast)
while fast:
if slow.val != fast.val:
return False
slow, fast = slow.next, fast.next
return True
if __name__ == "__main__":
a = Solution()
t = ListNode.list2ListNode([1, 2, 3, 3, 2, 1])
print(t)
print(a.isPalindrome(t))
elif head.val >= x:
if not eh:
eh = head
et = head
else:
et.next = head
et = head
else:
if not bh:
bh = head
bt = head
else:
bt.next = head
bt = head
head = next
if st:
st.next = eh
et = st if not et else et # 谁连大于区域的头谁变成et
if et:
et.next = bh
return sh if sh else (eh if eh else bh)
if __name__ == "__main__":
a = Solution()
l = ListNode.list2ListNode([1,4,3,2,5,2])
print(a.partition(l, 3))
break
p1 = p1.next
length += 1
return head
def insertionSortList1(self, head: ListNode) -> ListNode:
if not head:
return head
cur, nxt = head, head.next
dummy = ListNode(float('-inf'))
dummy.next = head
while nxt:
if nxt.val >= cur.val:
cur, nxt = nxt, nxt.next
else:
cur.next = nxt.next
pre1, pre2 = dummy, dummy.next
while nxt.val > pre2.val:
pre1, pre2 = pre2, pre2.next
pre1.next = nxt
nxt.next = pre2
nxt = cur.next
return dummy.next
if __name__ == "__main__":
a = Solution()
l = ListNode([4, 2, 1, 3])
print(l)
print(a.insertionSortList(l))
from 链表类 import ListNode
class Solution:
def getDecimalValue(self, head: ListNode) -> int:
ret = 0
if not head:
return []
while head:
if head.val == 0:
head = head.next
else:
break
while head:
ret = ret << 1
ret += head.val
head = head.next
return ret
if __name__ == "__main__":
a = Solution()
l = ListNode([1, 0, 1])
print(a.getDecimalValue(l))