2386. 找出数组的第 K 大和

2386. 找出数组的第 K 大和

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题目链接：2386. 找出数组的第 K 大和

代码如下：

//优先队列
//参考：https://leetcode.cn/problems/find-the-k-sum-of-an-array/solutions/2668280/zhao-chu-shu-zu-de-di-k-da-he-by-leetcod-z5kq
class Solution {
public:using pli=pair<long long,int>;long long kSum(vector<int>& nums, int k) {long long sum=0;for(int i=0;i<nums.size();i++){if(nums[i]>=0)sum+=nums[i];elsenums[i]*=-1;}sort(nums.begin(),nums.end());long long ret=0;priority_queue<pli,vector<pli>,greater<>>pq;pq.push({nums[0],0});for(int i=2;i<=k;i++){auto p=pq.top();pq.pop();ret=p.first;if(p.second==nums.size()-1)   continue;pq.push({ret+nums[p.second+1],p.second+1});pq.push({ret-nums[p.second]+nums[p.second+1],p.second+1});}return sum-ret;}
};