Bubble Sort
Repeatedly swap neighboring out-of-order elements until the whole list is sorted, simple but slow on large lists.
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Heap Sort
Build a heap from the list, then repeatedly pull out the largest element to sort in place in O(n log n).
Heap Sort Practice Problems
Easy
2 problemsMedium
3 problems- 84medium
Top K Frequent Elements
Find the k most frequently occurring elements in an array.
- 85medium
Kth Smallest Element in a Sorted Matrix
Find the kth smallest value in a matrix where each row and column is sorted.
- 86medium
K Closest Points to Origin
Find the k points closest to the origin on a 2D plane.
Hard
2 problemsRelated concepts
Merge Sort
Split the list in half, sort each half, then merge them back together in order, giving reliable O(n log n) time.
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Quick Sort
Pick a pivot, move smaller elements left and larger ones right, then repeat on each side to sort in place.
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Insertion Sort
Build the sorted list one element at a time, inserting each new element into its correct position as you go.
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Selection Sort
Repeatedly find the smallest remaining element and move it into place, simple to write but slow on large lists.
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Counting Sort
Count how many times each value appears, then rebuild the list in order, sorting in O(n) when values fall in a small range.
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