Today I have done leetcode's November LeetCoding Challenge with cpp.

November LeetCoding Challenge 12

Description

Remove Linked List Elements

Given the head of a linked list and an integer val, remove all the nodes of the linked list that has Node.val == val, and return the new head.

Example 1:

Input: head = [1,2,6,3,4,5,6], val = 6
Output: [1,2,3,4,5]

Example 2:

Input: head = [], val = 1
Output: []

Example 3:

Input: head = [7,7,7,7], val = 7
Output: []

Constraints:

• The number of nodes in the list is in the range [0, 10^4].
• 1 <= Node.val <= 50
• 0 <= val <= 50

Solution

class Solution {
public:
  ListNode* removeElements(ListNode* head, int val) {
    ListNode *newHead = new ListNode();
    ListNode *cur = newHead;
    while(head) {
      if(head->val != val) {
        cur->next = head;
        cur = cur->next;
      }
      head = head->next;
    }
    cur->next = nullptr;
    return newHead->next;
  }
};

// Accepted
// 66/66 cases passed (20 ms)
// Your runtime beats 84.92 % of cpp submissions
// Your memory usage beats 79.14 % of cpp submissions (15 MB)