合并两个有序链表成一个有序链表

迭代

• python版本

# class ListNode:
#     def __init__(self, x):
#         self.val = x
#         self.next = None

class Solution:
    def mergeTwoLists(self, l1: ListNode, l2: ListNode) -> ListNode:
        c = dummy =  ListNode(0)
        while l1 and l2:
            if l1.val<=l2.val:
                c.next = l1
                l1 = l1.next
            else:
                c.next =l2
                l2 =l2.next
            c =c.next
        c.next = l1 if l1 is not None else l2
        return dummy.next

• go版本

type ListNode struct {
    Val  int
    Next *ListNode
}

func mergeTwoLists(l1 *ListNode, l2 *ListNode) *ListNode {
    l := &ListNode{Val: 0}
    dummy:=l

    for l1 != nil && l2 != nil {
        if l1.Val <= l2.Val {
            l.Next = l1
            l1 = l1.Next
        } else {
            l.Next = l2
            l2 = l2.Next
        }
        l = l.Next
    }

    if l1 !=nil{
        l.Next=l1
    }else{
        l.Next=l2
    }
    return dummy.Next
}