To become strong in problem solving, especially for coding interviews, online assessments (OA), and platforms like HackerRank, Codility, and LeetCode, you should master.

Coding Patterns

1). Two Pointer Patterns – Move two indices toward each other to compare or find values

2). Fast and Slow Pointers – Detect cycles or distances in linked lists/arrays

3). Sliding Window – Fixed or dynamic-sized window to track elements in a range

4). Search & Decision Patterns
Binary Search – Search sorted space efficiently

5). Search Space Binary Search – Find answer using decision function (e.g. minimize/maximize)

6). Prefix and Math Patterns
Prefix Sum – Pre-compute cumulative values

7). Difference Array – Apply range updates in O(1)