def list2link(li):
n = len(li)
ans = ListNode(-1)
cur = ans
for i in range(n):
cur.next = ListNode(li[i])
cur = cur.next
return ans.next
def Mundane(self, l1, l2):
if not l1:
return l2
if not l2:
return l1
val = l1.val + l2.val
ans = ListNode(val % 10)
ans.next = self.addTwoNum(l1.next, l2.next)
if val >= 10:
ans.next = self.addTwoNum(ListNode(1), ans.next)
return ans
def Mundane(self, head):
ans = ListNode(-1)
ans.next = head
pre = ans
cur = ans.next
while cur and cur.next:
tmp = cur.next
pre.next = tmp
cur.next = tmp.next
tmp.next = cur
pre = cur
cur = cur.next
return ans.next
def swapPairs(self, head: ListNode) -> ListNode:
if not head or not head.next:
return head
cur = head.next
head.next = self.swapPairs(cur.next)
cur.next = head
return cur
def mergeKLists(self, lists) -> ListNode:
import heapq
dummy = ListNode(0)
p = dummy
head = []
for i in range(len(lists)):
if lists[i]:
heapq.heappush(head, (lists[i].val, i))
lists[i] = lists[i].next
while head:
val, idx = heapq.heappop(head)
p.next = ListNode(val)
p = p.next
if lists[idx]:
heapq.heappush(head, (lists[idx].val, idx))
lists[idx] = lists[idx].next
return dummy.next
def addTwoNumbers(self, l1: ListNode, l2: ListNode) -> ListNode:
s1 = ""
s2 = ""
p = l1
q = l2
while p:
s1 += str(p.val)
p = p.next
while q:
s2 += str(q.val)
q = q.next
res = str(int(s1) + int(s2))
ans = ListNode(-1)
pre = ans
for i in res:
pre.next = ListNode(i)
pre = pre.next
return ans.next
def addTwoNum(self, l1, l2):
ans = ListNode(-1)
cur = ans
#表示进位
flag = 0
while l1 or l2:
x = l1.val if l1 else 0
y = l2.val if l2 else 0
s = flag + x + y
flag = s // 10
#余数
cur.next = ListNode(s % 10)
cur = cur.next
if l1:
l1 = l1.next
if l2:
l2 = l2.next
if flag > 0:
cur.next = ListNode(1)
return ans.next
def addTwoNumbers(self, l1: ListNode, l2: ListNode) -> ListNode:
stack1 = []
stack2 = []
while l1:
stack1.append(l1.val)
l1 = l1.next
while l2:
stack2.append(l2.val)
l2 = l2.next
node = None
carry = 0
while stack1 or stack2:
x = stack1.pop() if stack1 else 0
y = stack2.pop() if stack2 else 0
val = x + y + carry
carry = val // 10
n = val % 10
cur = ListNode(n)
cur.next = node #!!!!!!!!!!!!!!!!!!尾插法
node = cur
# 判断最高位是否有进位
if carry != 0:
res = ListNode(carry)
res.next = cur
return res
return cur
def mergeTwoLists(self, l1: ListNode, l2: ListNode) -> ListNode:
ans = ListNode(-1)
cur = ans
while l1 and l2:
if l1.val <= l2.val:
cur.next = l1
l1 = l1.next
else:
cur.next = l2
l2 = l2.next
cur = cur.next
if l1:
cur.next = l1
if l2:
cur.next = l2
return ans.next