merge_two_sorted_lists

View Source

 1from utils import ListNode
 2from typing import Optional
 3
 4
 5# @leet start
 6class Solution:
 7    def mergeTwoLists(
 8        self, list1: Optional[ListNode], list2: Optional[ListNode]
 9    ) -> Optional[ListNode]:
10        """
11        To merge two sorted lists, we first create a dummy node, and then refer
12        to it to iterate through the list.
13        and then, while both lists are non-null, we choose the lower value and
14        add it to the list.
15        Otherwise, one of the lists is non-empty, and if that's the case, we
16        append that to the end of our current list.
17        At the end, we return the next node of the list.
18        """
19        head = ListNode()
20        curr = head
21
22        # then for each item in
23        while list1 and list2:
24            if list1.val < list2.val:
25                curr.next = list1
26                list1 = list1.next
27            else:
28                curr.next = list2
29                list2 = list2.next
30            curr = curr.next
31
32        if list1:
33            curr.next = list1
34        if list2:
35            curr.next = list2
36
37        return head.next
38
39
40# @leet end
41
42
43def test():
44    assert 2 + 2 == 4

class Solution: View Source

 7class Solution:
 8    def mergeTwoLists(
 9        self, list1: Optional[ListNode], list2: Optional[ListNode]
10    ) -> Optional[ListNode]:
11        """
12        To merge two sorted lists, we first create a dummy node, and then refer
13        to it to iterate through the list.
14        and then, while both lists are non-null, we choose the lower value and
15        add it to the list.
16        Otherwise, one of the lists is non-empty, and if that's the case, we
17        append that to the end of our current list.
18        At the end, we return the next node of the list.
19        """
20        head = ListNode()
21        curr = head
22
23        # then for each item in
24        while list1 and list2:
25            if list1.val < list2.val:
26                curr.next = list1
27                list1 = list1.next
28            else:
29                curr.next = list2
30                list2 = list2.next
31            curr = curr.next
32
33        if list1:
34            curr.next = list1
35        if list2:
36            curr.next = list2
37
38        return head.next

def mergeTwoLists( self, list1: Optional[utils.ListNode], list2: Optional[utils.ListNode]) -> Optional[utils.ListNode]: View Source

 8    def mergeTwoLists(
 9        self, list1: Optional[ListNode], list2: Optional[ListNode]
10    ) -> Optional[ListNode]:
11        """
12        To merge two sorted lists, we first create a dummy node, and then refer
13        to it to iterate through the list.
14        and then, while both lists are non-null, we choose the lower value and
15        add it to the list.
16        Otherwise, one of the lists is non-empty, and if that's the case, we
17        append that to the end of our current list.
18        At the end, we return the next node of the list.
19        """
20        head = ListNode()
21        curr = head
22
23        # then for each item in
24        while list1 and list2:
25            if list1.val < list2.val:
26                curr.next = list1
27                list1 = list1.next
28            else:
29                curr.next = list2
30                list2 = list2.next
31            curr = curr.next
32
33        if list1:
34            curr.next = list1
35        if list2:
36            curr.next = list2
37
38        return head.next

To merge two sorted lists, we first create a dummy node, and then refer to it to iterate through the list. and then, while both lists are non-null, we choose the lower value and add it to the list. Otherwise, one of the lists is non-empty, and if that's the case, we append that to the end of our current list. At the end, we return the next node of the list.

def test(): View Source

44def test():
45    assert 2 + 2 == 4