#devstudy #algorithmns #datastructures #problemsolving

Read Before Starting

STOP SKIPPING STEPS EVEN ON EASY QUESTIONS!!!!!!!!!! YOU WILL REGRET IT EVERYTIME!!!!!!!!!!!!!

Most Common Mistakes

EFFY PLEASE VISUALIZE/WRITE MORE TEST CASES – misinterpreting the problem bc going too fast – misunderstanding the problem bc going too fast – implementation issues with scoping

If Stuck

1. Can you reverse the interpretation?
2. Can you start the approach with the another input and/or direction?
3. Can you use a set or a map to store something you're manually reaching for at a later point?
4. Can you break down the problem more?
5. Did you make a table of cases to fully visualize the pattern or did you trust your assumptions? Don't trust your assumptions.

Interpretation Patterns

If input array is sorted then – Binary search – Two pointers

If asked for all permutations/subsets then – Backtracking

If given a tree then – DFS – BFS

If given a graph then – DFS – BFS

If given a linked list then – Two pointers

If recursion is banned then – Stack

If must solve in-place then – Swap corresponding values – Store one or more different values in the same pointer

If asked for maximum/minimum subarray/subset/options then – Dynamic programming

If asked for top/least K items then – Heap

If asked for common strings then – Map – Tree

Else – Map/Set for O(1) time & O(n) space – Sort input for O(nlogn) time and O(1) space

#devstudy #algorithmns #datastructures #problemsolving

1. Can you reverse the interpretation?
2. Can you start the approach with the another input and/or direction?
3. Can you use a set or a map to store something you're manually reaching for at a later point?
4. Can you break down the problem more?
5. Did you make a table of cases to fully visualize the pattern or did you trust your assumptions? Don't trust your assumptions.