MergeTwoSortedLists.cpp

/*
  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.
*/

/**
 * 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 = new ListNode(0);
	ListNode *curr = head;
	while(l1 && l2)
	{
	    if(l1->val < l2->val)
	    {
		curr->next = new ListNode(l1->val);
		curr = curr->next;
		l1 = l1->next;
	    }
	    else
	    {
		curr->next = new ListNode(l2->val);
		curr = curr->next;
		l2 = l2->next;
	    }
	}
	if(!l1)
	    curr->next = l2;
	if(!l2)
	    curr->next = l1;
	return head->next;
    }
};