GROKKING NOTES
I liked the way Grokking the coding interview organized problems into learnable patterns. However, the course is expensive and the majority of the time the problems are copy-pasted from leetcode. As the explanations on leetcode are usually just as good, the course really boils down to being a glorified curated list of leetcode problems.
So below I made a list of leetcode problems that are as close to grokking problems as possible.
- Pattern: Sliding Window
- https://leetcode.com/problems/maximum-subarray/ # Close enough
- https://leetcode.com/problems/minimum-size-subarray-sum/
- https://leetcode.com/problems/longest-substring-with-at-most-k-distinct-characters/
- https://leetcode.com/problems/fruit-into-baskets/
- https://leetcode.com/problems/longest-substring-without-repeating-characters/
- https://leetcode.com/problems/longest-repeating-character-replacement/
- https://leetcode.com/problems/max-consecutive-ones-iii/
- https://leetcode.com/problems/permutation-in-string/
- https://leetcode.com/problems/find-all-anagrams-in-a-string/
- https://leetcode.com/problems/minimum-window-substring/
- https://leetcode.com/problems/substring-with-concatenation-of-all-words/
- Pattern: Two Pointers
- https://leetcode.com/problems/two-sum/
- https://leetcode.com/problems/remove-duplicates-from-sorted-array/
- https://leetcode.com/problems/squares-of-a-sorted-array/
- https://leetcode.com/problems/3sum/
- https://leetcode.com/problems/3sum-closest/
- https://leetcode.com/problems/3sum-smaller/
- https://leetcode.com/problems/subarray-product-less-than-k/
- https://leetcode.com/problems/sort-colors/
- https://leetcode.com/problems/4sum/
- https://leetcode.com/problems/backspace-string-compare/
- https://leetcode.com/problems/shortest-unsorted-continuous-subarray/
- Pattern: Fast & Slow pointers
- https://leetcode.com/problems/linked-list-cycle/
- https://leetcode.com/problems/linked-list-cycle-ii/
- https://leetcode.com/problems/happy-number/
- https://leetcode.com/problems/middle-of-the-linked-list/
- https://leetcode.com/problems/palindrome-linked-list/
- https://leetcode.com/problems/reorder-list/
- https://leetcode.com/problems/circular-array-loop/
- Pattern: Merge Intervals
- https://leetcode.com/problems/merge-intervals/
- https://leetcode.com/problems/insert-interval/
- https://leetcode.com/problems/interval-list-intersections/
- https://leetcode.com/problems/meeting-rooms-ii/
- Could not find equivalent. Given a list of intervals with values, find the peak sum (i.e. if intervals are overlapping, sum their values)
- https://leetcode.com/problems/employee-free-time/
- Pattern: Cyclic Sort
- Couldn't find equivalent for the first question. The second question below encompasses the first one though. See https://leetcode.com/problems/missing-number/discuss/859510/C%2B%2B-O(N)-O(1)-using-Cyclic-Sort for how grokking the coding interview approached these problems. It uses the fact that we can sort the array in O(n) without comparison operators
- https://leetcode.com/problems/missing-number/
- https://leetcode.com/problems/find-all-numbers-disappeared-in-an-array/
- https://leetcode.com/problems/find-all-duplicates-in-an-array/
- combine https://leetcode.com/problems/find-the-duplicate-number/ and https://leetcode.com/problems/missing-number/
- https://leetcode.com/problems/first-missing-positive/
- https://leetcode.com/problems/kth-missing-positive-number/
- Pattern: In-place Reversal of a LinkedList
- https://leetcode.com/problems/reverse-linked-list/
- https://leetcode.com/problems/reverse-linked-list-ii/
- https://leetcode.com/problems/reverse-nodes-in-k-group/
- Next question is the same, but alternate each subgroup
- https://leetcode.com/problems/rotate-list/
- Pattern: Tree Breadth First Search
- https://leetcode.com/problems/binary-tree-level-order-traversal/
- https://leetcode.com/problems/binary-tree-level-order-traversal-ii/
- https://leetcode.com/problems/binary-tree-zigzag-level-order-traversal/
- https://leetcode.com/problems/minimum-depth-of-binary-tree/
- https://leetcode.com/problems/inorder-successor-in-bst/ # Close, not exact
- https://leetcode.com/problems/populating-next-right-pointers-in-each-node/ # Close, grokk assumes non-perfect tree
- Next question is the same, but connect end nodes to the next level instead of null
- https://leetcode.com/problems/binary-tree-right-side-view/
- Pattern: Tree Depth First Search
- Pattern: Two Heaps
- Pattern: Subsets
- Pattern: Modified Binary Search
- Pattern: Bitwise XOR
- Pattern: Top 'K' elements
- Pattern: K-way merge
- Pattern: 0/1 Knapsack
- Pattern: Topological Sort
https://leetcode.com/problems/kth-largest-element-in-an-array/