def reverseBetween(self, head, m, n): """ :type head: ListNode :type m: int :type n: int :rtype: ListNode """ if head is None or head.next is None or m == n: return head headnode = ListNode(-1) headnode.next = head anchor = headnode for _ in range(m - 1): anchor = anchor.next a = anchor.next b = a.next c = b.next k = n - m for _ in range(k): b.next = a if c: a, b, c = b, c, c.next else: a, b = b, c anchor.next.next = b anchor.next = a return headnode.next
def addTwoNumbers(self, l1, l2): headnode = ListNode(0) p = headnode p1, p2 = l1, l2 carry = 0 # 处理等长部分 while p1 and p2: val = p2.val + p1.val + carry p.next = ListNode(val % 10) carry = val // 10 p, p1, p2 = p.next, p1.next, p2.next # 处理不等长的部分 while p1: val = p1.val + carry p.next = ListNode(val % 10) carry = val // 10 p, p1 = p.next, p1.next while p2: val = p2.val + carry p.next = ListNode(val % 10) carry = val // 10 p, p2 = p.next, p2.next if carry > 0: p.next = ListNode(carry) return headnode.next
def addAtHead(self, val): """ Add a node of value val before the first element of the linked list. After the insertion, the new node will be the first node of the linked list. :type val: int :rtype: void """ newnode = ListNode(val) newnode.next, self.headnode.next = self.headnode.next, newnode if self.length == 0: self.tail = newnode self.length += 1
def addTwoNumbers(self, l1, l2): """ :type l1: ListNode :type l2: ListNode :rtype: ListNode """ bonus = 0 c = l1 len1 = 0 while c: len1 += 1 c = c.next c = l2 len2 = 0 while c: len2 += 1 c = c.next if len1 < len2: l1, l2 = l2, l1 prettyPrintLinkedList(l1) prettyPrintLinkedList(l2) res = l1 while l2: bonus, l1.val = divmod(l1.val+l2.val+bonus, 10) last = l1 l1 = l1.next l2 = l2.next while bonus and l1: bonus, l1.val = divmod(l1.val+bonus, 10) last = l1 l1 = l1.next if bonus: last.next = ListNode(1) return res
def insertionSortList(self, head): """ :type head: ListNode :rtype: ListNode """ if head is None or head.next is None: return head sorted = head unsorted = head.next inf = ListNode(float("inf")) sorted.next = inf # sorted.next.next = sorted while unsorted: c = sorted while c.val < unsorted.val: c = c.next temp = unsorted unsorted = unsorted.next temp.next = c.next c.next = temp c.val, temp.val = temp.val, c.val while True: if c.next.val == float("inf"): break c = c.next c.next = None return sorted
def __init__(self): """ Initialize your data structure here. """ self.headnode = ListNode(None) self.length = 0 self.tail = None
def addAtTail(self, val): """ Append a node of value val to the last element of the linked list. :type val: int :rtype: void """ newnode = ListNode(val) if self.tail: self.tail.next = newnode else: # the first node self.headnode.next = newnode self.tail = newnode self.length += 1
def _get(self, index): """ Get the value of the index-th node in the linked list. If the index is invalid, return -1. :type index: int :rtype: int """ if index >= self.length: return ListNode(-1) else: c = self.headnode.next for _ in range(index): c = c.next return c
def deleteDuplicates(self, head): """ :type head: ListNode :rtype: ListNode """ headnode = ListNode(None) headnode.next = head delete = False p = headnode # prev c = head # current while c: while c.next and c.val == c.next.val: c.next = c.next.next if not delete: delete = True if delete: c = c.next p.next = c delete = False else: c = c.next p = p.next return headnode.next
def addAtIndex(self, index, val): """ Add a node of value val before the index-th node in the linked list. If index equals to the length of linked list, the node will be appended to the end of linked list. If index is greater than the length, the node will not be inserted. :type index: int :type val: int :rtype: void """ if index < 0 or index > self.length: return None if index == 0: self.addAtHead(val) elif index == self.length: self.addAtTail(val) else: insert_point = self._get(index) newnode = ListNode(insert_point.val) newnode.next = insert_point.next insert_point.next = newnode insert_point.val = val self.length += 1 if insert_point is self.tail: self.tail = insert_point.next