K Closest Points to Origin

We have a list of points on the plane. Find the K closest points to the origin (0, 0). (Here, the distance between two points on a plane is the Euclidean distance.) You may return the answer in any order. The answer is guaranteed to be unique (except for the order that it is in.) Example 1 Input: points = [[1,3],[-2,2]], K = 1 Output: [[-2,2]] Explanation: The distance between (1, 3) and the origin is sqrt(10).

by lek tin in "algorithm" access_time 3-min read

Kth Largest Element in an Array

Find the kth largest element in an unsorted array. Note that it is the kth largest element in the sorted order, not the kth distinct element. Example 1 Input: [3,2,1,5,6,4] and k = 2 Output: 5 Example 2 Input: [3,2,3,1,2,4,5,5,6] and k = 4 Output: 4 Note You may assume k is always valid, 1 ≤ k ≤ array's length. Solution Average time complexity: O(n) if we don’t need the sorted output, otherwise O(n+kLogk)

by lek tin in "algorithm" access_time 2-min read