Time complexity (Big-O notation)

Space complexity

Searching (linear, binary)

Sorting (bubble, merge, quicksort)

Recursion & divide and conquer

Dynamic programming

Greedy algorithms

Graph traversal (BFS, DFS)

String matching (Naive, KMP, Boyer-Moore)

Edit distance / Levenshtein distance

Longest Common Subsequence

Viterbi algorithm

CYK / Earley parsing algorithms