LeetCode in Kotlin
21. Merge Two Sorted Lists
Easy
Merge two sorted linked lists and return it as a sorted list. The list should be made by splicing together the nodes of the first two lists.
Example 1:
Input: l1 = [1,2,4], l2 = [1,3,4]
Output: [1,1,2,3,4,4]
Example 2:
Input: l1 = [], l2 = []
Output: []
Example 3:
Input: l1 = [], l2 = [0]
Output: [0]
Constraints:
- The number of nodes in both lists is in the range
[0, 50]. -100 <= Node.val <= 100- Both
l1andl2are sorted in non-decreasing order.
Solution
import com_github_leetcode.ListNode
/*
* Example:
* var li = ListNode(5)
* var v = li.`val`
* Definition for singly-linked list.
* class ListNode(var `val`: Int) {
* var next: ListNode? = null
* }
*/
class Solution {
fun mergeTwoLists(list1: ListNode?, list2: ListNode?): ListNode? {
var l1 = list1
var l2 = list2
var list: ListNode? = ListNode(-1)
val head = list
while (l1 != null || l2 != null) {
if (l1 != null && l2 != null) {
if (l1.`val` <= l2.`val`) {
list!!.next = ListNode(l1.`val`)
l1 = l1.next
} else {
list!!.next = ListNode(l2.`val`)
l2 = l2.next
}
} else if (l1 != null) {
list!!.next = ListNode(l1.`val`)
l1 = l1.next
} else {
list!!.next = ListNode(l2!!.`val`)
l2 = l2.next
}
list = list.next
}
return head!!.next
}
}