Kth Largest Element in an Array

Category

Heap / Priority Queue

Checkbox

Difficulty

Medium

Index

Key Ideas

The key idea to solve the problem of finding the kth largest element in an array is to use a heap or priority queue to efficiently keep track of the k largest elements while traversing the array.

Problem Number

215

Problem Summary

The problem "Kth Largest Element in an Array" (Problem Number: 215) is categorized as a medium-level problem in LeetCode. It involves finding the Kth largest element in an unsorted integer array. Some key pitfalls to consider when solving this problem include handling edge cases, choosing an efficient algorithm, and considering the trade-off between time complexity and space complexity.

Solution Summary

The best solution to find the kth largest element in an array is to use a min-heap or a priority queue. 1. Create a min-heap/priority queue with the first k elements from the array. 2. For each remaining element in the array, if it is larger than the smallest element in the min-heap/priority queue, remove the smallest element and insert the new element. 3. At the end, the top element of the min-heap/priority queue will be the kth largest element in the array. This solution has a time complexity of O(n log k), where n is the size of the array and k is the position of the desired largest element.