How to Compute Kth Largest Element in a Stream?
- 时间:2020-09-28 16:28:51
- 分类:网络文摘
- 阅读:107 次
Design a class to find the kth largest element in a stream. Note that it is the kth largest element in the sorted order, not the kth distinct element.
Your KthLargest class will have a constructor which accepts an integer k and an integer array nums, which contains initial elements from the stream. For each call to the method KthLargest.add, return the element representing the kth largest element in the stream.
Example:
int k = 3;
int[] arr = [4,5,8,2];
KthLargest kthLargest = new KthLargest(3, arr);
kthLargest.add(3); // returns 4
kthLargest.add(5); // returns 5
kthLargest.add(10); // returns 5
kthLargest.add(9); // returns 8
kthLargest.add(4); // returns 8
Note:
You may assume that nums’ length ≥ k-1 and k ≥ 1.
Compute the K-th Largest using Priority Queue
In the constructor, we store the K and construct a priority queue. Then we need to push the elements into the priority queue.
When we add another element to the priority queue, we need to pop extra elements until we have exactly K elements internally in the priority queue.
Adding one element to the priority queue takes O(logN) time complexity.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 | class KthLargest { public: KthLargest(int k, vector<int>& nums) { this->kth = k; for (const auto &n: nums) { pq.push(n); } } int add(int val) { pq.push(val); while (kth < pq.size()) { pq.pop(); } return pq.top(); } private: int kth; priority_queue<int, vector<int>, std::greater<int>> pq; }; /** * Your KthLargest object will be instantiated and called as such: * KthLargest* obj = new KthLargest(k, nums); * int param_1 = obj->add(val); */ |
class KthLargest { public: KthLargest(int k, vector<int>& nums) { this->kth = k; for (const auto &n: nums) { pq.push(n); } } int add(int val) { pq.push(val); while (kth < pq.size()) { pq.pop(); } return pq.top(); } private: int kth; priority_queue<int, vector<int>, std::greater<int>> pq; }; /** * Your KthLargest object will be instantiated and called as such: * KthLargest* obj = new KthLargest(k, nums); * int param_1 = obj->add(val); */
–EOF (The Ultimate Computing & Technology Blog) —
推荐阅读:九个好的饮食习惯有助于你远离癌症 莲藕生吃和熟吃的保健功效不相同 四种酒这样喝可以变保健良药 美食伟哥枸杞怎么吃有助于壮阳 枸杞子食疗配方助电脑族保护眼睛 胡萝卜怎么吃营养最丰富防癌又明目 过量食用生姜有增大患肝癌的风险 长芽了不能吃的食物有哪些? 哪些食物发芽了也可继续食用 饮食养生:处暑饮食注重健脾化湿
- 评论列表
-
- 添加评论