剑指Offer 18. 删除链表的节点

/**
 * Definition for singly-linked list.
 * function ListNode(val) {
 *     this.val = val;
 *     this.next = null;
 * }
 */
/**
 * @param {ListNode} head
 * @param {number} val
 * @return {ListNode}
 */
var deleteNode = function(head, val) {
    let cur = head
    let prev = null
    while(cur !== null) {
        if (head.val === val) {
            head = head.next
        } else if (cur.val === val) {
            prev.next = cur.next
        } else {
            prev = cur
        }
        cur = cur.next
    }
    return head
};