Heap

Connect ropes with minimum cost using greedy approach with heap

Find the k largest elements from an unsorted array

Find the k smallest elements from an unsorted array

Design data structure to find median from continuous stream of integers

Find furthest building reachable using optimal allocation of bricks and ladders

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.

Find the kth largest element in an unsorted array

Find kth smallest element in row and column sorted matrix using heap

Design a stack that supports push, pop, top, peekMax, and popMax operations

Maximize array sum by flipping signs of k elements using greedy heap approach

Find minimum number of meeting rooms required using heap

Merge k sorted arrays into one sorted array using heap

Merge k sorted linked lists into one sorted linked list

Find minimum refueling stops to reach target using greedy max-heap approach

Find minimum removals to reduce array size by half using greedy heap approach

Solve LC 767 with a greedy priority queue (max-heap). Learn the maxFreq ≤ ceil(n/2) condition + proof. O(n log k). Practice now.

Find the maximum element in each sliding window of size k

Hard LC 480: rolling median via sliding window + two heaps w/ lazy deletion. O(n log k) time, O(k) space. Step-by-step solution—prep now.

Sort characters in string by frequency using heap or bucket sort

Schedule tasks with cooling period using greedy approach with heap

Given an integer array and k, return the k most frequent elements.

Solve LeetCode 347 Top K Frequent Elements (Medium) with frequency map + bucket sort O(n) or min-heap O(n log k). Step-by-step for interviews.

What is an ugly number? Solve n-th ugly number (2,3,5) with PriorityQueue + HashSet dedupe. O(n log n). Step-by-step—practice now.