merge-two-sorted-lists

Easy Merge
Two Sorted Lists
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38%

Accepted

Merge two sorted (ascending) linked lists and return it as a new sorted list. The new sorted list should be made by splicing together the nodes of the two lists and sorted in ascending order.

Have you met this question in a real interview?

Yes

Example

Given

1->3->8->11->15->null

,

2->null

,
return

1->2->3->8->11->15->null

.

/**
 * Definition for ListNode.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int val) {
 *         this.val = val;
 *         this.next = null;
 *     }
 * }
 */ 
public class Solution {
    /**
     * @param ListNode l1 is the head of the linked list
     * @param ListNode l2 is the head of the linked list
     * @return: ListNode head of linked list
     */
    public ListNode mergeTwoLists(ListNode l1, ListNode l2) {
        ListNode dummy = new ListNode(0);
        ListNode point = dummy;
        while(l1 != null && l2 != null){
            if(l1.val < l2.val){
                point.next = l1;
                l1 = l1.next;
            }else{
                point.next = l2;
                l2 = l2.next;
            }
            point = point.next;
        }
        if(l1 != null){
            point.next = l1;
        }else{
            point.next = l2;
        }
        return dummy.next;
    }
}