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.
Show Tags Have you met this question in a real interview? Yes No
Discuss
#include/** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListNode(int x) : val(x), next(NULL) {} * }; */ struct ListNode { int val; ListNode *next; ListNode(int x) : val(x), next(NULL) {} }; class Solution { public: ListNode* mergeTwoLists(ListNode* l1, ListNode* l2) { if (!l1) { return l2; } if (!l2) { return l1; } ListNode Head(0); ListNode *Pre = &Head; while(l1 && l2) { if (l1->val < l2->val) { Pre->next = l1; l1 = l1->next; Pre = Pre->next; } else { Pre->next = l2; l2 = l2->next; Pre = Pre->next; } } while (l1) { Pre->next = l1; l1 = l1->next; Pre = Pre->next; } while(l2) { Pre->next = l2; l2 = l2->next; Pre = Pre->next; } return Head.next; } };