Merge Two Sorted Lists

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.

class Solution {public:ListNode* mergeTwoLists(ListNode* l1, ListNode* l2) {if (!l1)return l2;if (!l2)return l1;ListNode *list = NULL;ListNode *current = NULL;list = (l1->val <= l2->val) ? l1 : l2;if (list == l1)l1 = l1->next;elsel2 = l2->next;current = list;while (l1 && l2){if (l1->val <= l2->val){current->next = l1;l1 = l1->next;}else{current->next = l2;l2 = l2->next;}current = current->next;}while (l1){current->next = l1;l1 = l1->next;current = current->next;}while (l2){current->next = l2;l2 = l2->next;current = current->next;}return list;}};