刷 LeetCode 从零开始学 GoLang（7）：21. Merge Two Sorted Lists

题目描述

Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists.

Example:

Input: 1->2->4, 1->3->4
Output: 1->1->2->3->4->4

GoLang 语法：结构体 struct

1. 结构体的定义

type struct_variable_type struct {
   member definition;
   member definition;
   ...
   member definition;
}

2. 结构体的字面值(Literal)

variable_name := structure_variable_type {value1, value2...valuen}
或
variable_name := structure_variable_type { key1: value1, key2: value2..., keyn: valuen}

3. 使用结构体变量，如果要访问结构体成员，需要使用点号 ​​.​​ 操作符
4. 使用结构体指针访问结构体成员，也是使用 ​​.​​ 操作符

AC 代码

/**
 * Definition for singly-linked list.
 * type ListNode struct {
 *     Val int
 *     Next *ListNode
 * }
 */
func mergeTwoLists(l1 *ListNode, l2 *ListNode) *ListNode {
    var head *ListNode = nil
    var tail *ListNode = nil
    
    for l1 != nil || l2 != nil {
        var cur *ListNode = nil
        
        // 使用结构体指针访问结构体成员，使用 "." 操作符
        if l2 == nil || (l1 != nil && l2.Val >= l1.Val) {
            cur = l1
            l1 = l1.Next
        } else {
            cur = l2
            l2 = l2.Next
        }
        
        // 插入 cur 节点到新链表
        if head == nil {
            head, tail = cur, cur
        } else {
            tail.Next = cur
            tail = tail.Next
        }
        tail.Next = nil
    }
    
    return head
}