The sword means offer_ to divide duplicate nodes in the linked list

If there are duplicate nodes in a sorted linked list, please delete the duplicate nodes in the linked list. The duplicate nodes are not retained.

Input: 1->2->3->3->4->4->5 Output: 1->2->5Copy the code

If the virtual header is used in the same way, q = q.ext determines whether the length is 1

/** * Definition for singly-linked list. * function ListNode(val) { * this.val = val; * this.next = null; *} * /
/ * * *@param {ListNode} head
 * @return {ListNode}* /
var deleteDuplication = function(head) {
    let dummy = new ListNode(-1);
    dummy.next = head;
    
    let p = dummy;
    while(p.next){
        let q = p.next;
        while(q && p.next.val === q.val) q = q.next;
        
        // Check whether the length is 1
        if(p.next.next === q) p = p.next;
        else p.next = q;
    }
    
    return dummy.next;
    
};
Copy the code