Delete Node in a Linked List

Write a function to delete a node (except the tail) in a singly linked list, given only access to that node.

Supposed the linked list is 1 -> 2 -> 3 -> 4 and you are given the third node with value 3, the linked list should become 1 -> 2 -> 4 after calling your function.

Shift the val left by 1, delete the tail.

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution {
public:
    void deleteNode(ListNode* node) {
        ListNode * prev = node;
        ListNode * curr = node->next; // question gurantee that curr is not nullptr
        while(curr->next != nullptr){
            prev->val = curr->val;
            curr = curr->next;
            prev = prev->next;
        }
        prev->val = curr->val;
        prev->next = nullptr;
        delete curr;
    }
};