203. Remove Linked List Elements

tags: Easy、Linked-List

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.

解法:

用簡單的移除list node的方式去解，要記得先處理頭指針

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     struct ListNode *next;
 * };
 */
struct ListNode* removeElements(struct ListNode* head, int val) {
    while (head != NULL && head->val == val) {
        struct ListNode *temp = head;
        head = head->next;
        free(temp);
    }    
    struct ListNode *current = head;

    while(current != NULL && current->next != NULL) {
        if (current->next->val == val) {
            struct ListNode *temp = current->next;
            current->next = current->next->next;
            free(temp);
        }
        
        else {
            current = current->next;
        }
    }
    return head; 
}