| Table of Contents | ||
|---|---|---|
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Merge Two Sorted Lists 合并两个有序列表
https://leetcode.com/problems/merge-two-sorted-lists/
...
| Code Block |
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/**
* Definition for singly-linked list.
* type ListNode struct {
* Val int
* Next *ListNode
* }
*/
func mergeTwoLists(list1 *ListNode, list2 *ListNode) *ListNode {
dummy := &ListNode{}
p := dummy
p1 := list1
p2 := list2
for p1 != nil && p2 != nil {
if p1.Val < p2.Val {
p.Next = p1
p1 = p1.Next
p = p.Next
} else {
p.Next = p2
p2 = p2.Next
p = p.Next
}
}
if p1 != nil {
p.Next = p1
}
if p2 != nil {
p.Next = p2
}
return dummy.Next
} |
Partition List 分隔链表
https://leetcode.com/problems/partition-list/
...
| Code Block | ||
|---|---|---|
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/**
* Definition for singly-linked list.
* type ListNode struct {
* Val int
* Next *ListNode
* }
*/
func partition(head *ListNode, x int) *ListNode {
dummy1 := &ListNode{}
dummy2 := &ListNode{}
p1 := dummy1
p2 := dummy2
for p := head; p != nil; p = p.Next {
if p.Val < x {
p1.Next = p
p1 = p1.Next
} else {
p2.Next = p
p2 = p2.Next
}
}
p1.Next = dummy2.Next
p2.Next = nil
return dummy1.Next
} |
Merge k Sorted Lists 合并 k 个有序列表
https://leetcode.com/problems/merge-k-sorted-lists/
...
| Code Block | ||
|---|---|---|
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/**
* Definition for singly-linked list.
* type ListNode struct {
* Val int
* Next *ListNode
* }
*/
func mergeKLists(lists []*ListNode) *ListNode {
dummy := &ListNode{}
p := dummy
pq := &NodeHeap{}
for _, l := range lists {
if l != nil {
heap.Push(pq, l)
}
}
for pq.Len() != 0 {
v := heap.Pop(pq).(*ListNode)
p.Next = v
p = p.Next
if v.Next != nil {
heap.Push(pq, v.Next)
}
}
return dummy.Next
}
type NodeHeap []*ListNode
func (h NodeHeap) Len() int {
return len(h)
}
func (h NodeHeap) Swap(i, j int) {
h[i], h[j] = h[j], h[i]
}
func (h NodeHeap) Less(i, j int) bool {
return h[i].Val < h[j].Val
}
func (h *NodeHeap) Push(x any) {
*h = append(*h, x.(*ListNode))
}
func (h *NodeHeap) Pop() any {
n := len(*h)
v := (*h)[n-1]
*h = (*h)[:n-1]
return v
} |
Remove Nth Node From End of List 删除链表的倒数第 N 个结点
https://leetcode.com/problems/remove-nth-node-from-end-of-list/
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| Code Block | ||
|---|---|---|
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/**
* Definition for singly-linked list.
* type ListNode struct {
* Val int
* Next *ListNode
* }
*/
func removeNthFromEnd(head *ListNode, n int) *ListNode {
dummy := &ListNode{Next: head}
prev := findFromEnd(dummy, n+1)
prev.Next = prev.Next.Next
return dummy.Next
}
func findFromEnd(head *ListNode, n int) *ListNode {
p1 := head
p2 := head
for i := 0; i < n; i++ {
p2 = p2.Next
}
for p2 != nil {
p2 = p2.Next
p1 = p1.Next
}
return p1
} |
Middle of the Linked List 链表的中间结点（找到链表的中点）
https://leetcode.com/problems/middle-of-the-linked-list/
...
原链为奇数 [0, 2p+1) → 新链为偶数 [0, 2p+2) → 取中点获得新链的 p+1 号节点 → 等同原链的 p 号节点
原链为偶数 [0, 2p) → 新链为奇数 [0, 2p+1) → 取中点获得新链的 p 号节点 → 等同原链的 p-1 号节点
Delete the Middle Node of a Linked List 删除链表的中间节点
https://leetcode.com/problems/delete-the-middle-node-of-a-linked-list/
...
在 https://singee.atlassian.net/wiki/spaces/algorithm/pages/edit-v2/49316106#Middle-of-the-Linked-List 的基础上，记录 slow 前面那个指针
Linked List Cycle 环形链表（判断链表是否有环）
https://leetcode.com/problems/linked-list-cycle/
| Code Block | ||
|---|---|---|
| ||
/**
* Definition for singly-linked list.
* type ListNode struct {
* Val int
* Next *ListNode
* }
*/
func hasCycle(head *ListNode) bool {
slow := head
fast := head
for fast != nil && fast.Next != nil {
slow = slow.Next
fast = fast.Next.Next
if slow == fast {
return true
}
}
return false
} |
Linked List Cycle II 环形链表 II （找到环形链表的起点）
https://leetcode.com/problems/linked-list-cycle-ii/
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解法说明：快慢指针相遇时，让其中一个指针指回起点，再重新同速行进再次遇到则为环起点
Intersection of Two Linked Lists 相交链表（判断两个链表是否相交）
https://leetcode.com/problems/intersection-of-two-linked-lists/description/
...