21. Merge Two Sorted Lists #

Problem #

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

Problem Summary #

Merge two sorted linked lists.

Solution Approach #

Just follow the problem statement.

Code #


package leetcode

/**
 * Definition for singly-linked list.
 * type ListNode struct {
 *     Val int
 *     Next *ListNode
 * }
 */
func mergeTwoLists(l1 *ListNode, l2 *ListNode) *ListNode {
	if l1 == nil {
		return l2
	}
	if l2 == nil {
		return l1
	}
	if l1.Val < l2.Val {
		l1.Next = mergeTwoLists(l1.Next, l2)
		return l1
	}
	l2.Next = mergeTwoLists(l1, l2.Next)
	return l2
}