Grokking the coding interview equivalent leetcode problems

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/