0021. Merge Two Sorted Lists | LeetCode Cookbook

[halfrost]

https://books.halfrost.com/leetcode/ChapterFour/0001~0099/0021.Merge-Two-Sorted-Lists/

[hujun2020]

func mergeTwoLists(l1 *LinkList, l2 *LinkList) *LinkList {
	 head := &LinkList{Next:l1}   //虚拟头结点
	 cur := head
	 for l1 != nil && l2 !=nil{
	 	 if l1.Val>=l2.Val{
	 	 	cur.Next=l2
	 	 	l2 = l2.Next
		 }else {
		 	cur.Next=l1
		 	l1 = l1.Next
		 }
		 cur = cur.Next
	 }
	 if l1 == nil{
	 	cur.Next=l2
	 }else{
		 cur.Next=l1
	 }
	 return head.Next
}

[alan1914]

 // java -> 递归
 public ListNode mergeTwoLists(ListNode list1, ListNode list2) {

        if (null == list1) {
            return list2;
        }
        if (null == list2) {
            return list1;
        }
        if (list1.val <= list2.val) {
            list1.next = mergeTwoLists(list1.next, list2);
            return list1;
        } else {
            list2.next = mergeTwoLists(list2.next, list1);
            return list2;
        }

    }