【Easy】174. Remove Nth Node From End of List

Given a linked list, remove the nth node from the end of list and return its head.

Notice:

• The minimum number of nodes in list is n.

Example:

Given linked list: 1->2->3->4->5->null, and n = 2.

After removing the second node from the end, the linked list becomes 1->2->3->5->null.

解题思路

唯一要注意的是slow和fast的初始值。

核心代码

    ListNode slow = dummy, fast = dummy;

    for (int i = 0; i < n; i++) {
        fast = fast.next;
    }

    while (fast != null && fast.next != null) {
        slow = slow.next;
        fast = fast.next;
    }

    slow.next = slow.next.next;

时间空间复杂度

O(n) + S(1)