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.
Subscribe to see which companies asked this question.
/** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListNode(int x) : val(x), next(NULL) {} * }; */ class Solution { public: ListNode* mergeTwoLists(ListNode* l1, ListNode* l2) { ListNode * head; ListNode * ptr = head; while(l1 != NULL || l2 != NULL){ ListNode * cur = NULL; if(l1 == NULL){ cur = l2; l2 = l2->next; } else if(l2 == NULL){ cur = l1; l1 = l1->next; } else{ if(l1->val < l2->val){ cur = l1; l1 = l1->next; } else{ cur = l2; l2 = l2->next; } } ptr->next = cur; ptr = ptr->next; } return head->next; } };