题目:
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.
提示:
此题其实和MergeSort的Merge部分的步骤是类似的。
代码:
/** * 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) { if (l1 == NULL) return l2; if (l2 == NULL) return l1; ListNode pre_head(0); ListNode *node = &pre_head; while (l1 && l2) { if (l1->val < l2->val) { node->next = l1; l1 = l1->next; } else { node->next = l2; l2 = l2->next; } node = node->next; } node->next = l1 ? l1 :l2; return pre_head.next; } };