Merge Two Sorted Lists:

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 l1 and l2 are sorted in non-decreasing order.

Merge Two Sorted Lists

Solution:

                                        /**
                                        * @param {ListNode} l1
                                        * @param {ListNode} l2
                                        * @return {ListNode}
                                        */
                                        var mergeTwoLists = function(l1, l2) {
                                            var dummy = {
                                            val : -1,
                                            next : null
                                            };
                                            var curr = dummy;
                                            while (l1 && l2) {
                                                if (l1.val > l2.val) {
                                                    curr.next = l2;
                                                    l2 = l2.next;
                                                } else {
                                                    curr.next = l1;
                                                    l1 = l1.next;
                                                }
                                                curr = curr.next;
                                            }
                                            
                                            curr.next = l1 || l2;
                    
                                            return dummy.next;
                                            
                                        };
                          

Output:

Merge Two Sorted Lists

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