203_Remove-Linked-List-Elements.cpp

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode() : val(0), next(nullptr) {}
 *     ListNode(int x) : val(x), next(nullptr) {}
 *     ListNode(int x, ListNode *next) : val(x), next(next) {}
 * };
 */
class Solution {
public:
    ListNode* removeElements(ListNode* head, int val) {
        if(head == nullptr) return head;
        if(head->val == val) return removeElements(head->next, val);

        ListNode* indirect = head;

        while(indirect->next!=nullptr){
            if(indirect->next->val == val){
                indirect->next = indirect->next->next;
            }else{
                indirect = indirect->next;
            }
        }
        return head;
    }
};