题目如下
数据范围
使用自定义的仿函数作为比较器。对于n个列表每轮都取到链表头进入队列中最后统一接到哨兵结点(即new出来的头结点)
通过代码
/*** Definition for singly-linked list.* struct ListNode {* int val;* ListNode *next;* ListNode() : val(0), next(nullptr) {}* ListNode(int x) : val(x), next(nullptr) {}* ListNode(int x, ListNode *next) : val(x), next(next) {}* };*/
class Solution {
public:struct cmp {bool operator()(ListNode *a, ListNode *b) {return a->val > b->val;}};ListNode* mergeKLists(vector<ListNode*>& lists) {priority_queue<ListNode*,vector<ListNode*>,cmp> q;bool flag = false;ListNode* ans = new ListNode(-1);ListNode* f = ans;int n = lists.size();if(n == 0)return nullptr;while(true){flag = false;for(int i = 0;i < n;i++){if(lists[i] != nullptr){q.push(lists[i]);lists[i] = lists[i] -> next;flag = true;}}if(!flag)break;}while(!q.empty()){f -> next = q.top();q.pop();f = f -> next;}f -> next = nullptr;return ans -> next;}
};