class Solution {
public:
    ListNode *mergeKLists(vector<ListNode *> &lists) {
        // 扔到数组里可以解决
        vector<int> arr;
        ListNode* head = new ListNode(0);
        ListNode* ans = head;
        int n = lists.size();
        for (int i = 0; i < n; ++i) {
            while(lists[i]) {
                arr.push_back(lists[i]->val);
                lists[i] = lists[i]->next;
            }
        }
        sort(arr.begin(), arr.end());
        for (auto a : arr) {
            // 每次都生成新的下一个链表节点
            head->next = new ListNode(a);
            head = head->next;
        }
        return ans->next;
    }
};