The coverage counter behind Minimum Window Substring
6 min read Walking Minimum Window Substring from the brute-force baseline to the O(n) sliding window that tracks coverage with a single counter. Read article
Coding Interview Questions
Coding Interview Questions
3Sum and the three places duplicates sneak back in
7 min read Why 3Sum sorts first, where the duplicate skips go, and what interviewers ask once your two-pointer solution compiles. Read article
Coding Interview Questions
How the sliding window solves Longest Substring Without Repeats
6 min read The two-pointer window that turns a quadratic substring scan into one linear pass, plus the stale-index guard that quietly breaks the fast version. Read article
Coding Interview Questions
The sort-then-sweep trick behind merge intervals
6 min read How sorting by start time turns merge intervals, insert interval, and meeting rooms into one linear sweep. Read article
Coding Interview Questions
Trapping Rain Water, from brute force to two pointers
6 min read The trapped-water problem has three standard solutions, and the gap between them is what an interviewer is actually grading. Read article
Coding Interview Questions
Two Sum, and the hash-map habit it’s really testing
6 min read Two Sum looks trivial, but the jump from the brute-force pair check to the one-pass hash map is the exact skill interviewers are screening for. Read article
