题解 | #调整牛群顺序#

/**
 * struct ListNode {
 *	int val;
 *	struct ListNode *next;
 *	ListNode(int x) : val(x), next(nullptr) {}
 * };
 */
class Solution {
public:
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param head ListNode类 
     * @param n int整型 
     * @return ListNode类
     */
    ListNode* moveNthToEnd(ListNode* head, int n) 
    {
        // write code here
        vector<int> data;
        while(head != NULL)
        {
            data.push_back(head->val);
            head = head->next;
        }
        int a = data[data.size() - n];
        data[data.size() - n] = -1;
        data.push_back(a);
        ListNode* prev = new ListNode(0);
        ListNode* result = prev;
        for (int i = 0;i < data.size();++i)
        {
            if (data[i] == -1)
            {
                continue;
            }
            else
            {
                ListNode* cur = new ListNode(data[i]);
                prev->next = cur;
                prev = cur;
            }
        }
        return result->next;
    }
};

最好理解的方法