Coding Interview
Jason Yang · 04 Aug, 2026
Backtracking is a decision-tree DFS with an undo step. The choose/explore/unchoose template in Java, pruning dead branches, and the duplicate-skipping trick.
Coding Interview
Jason Yang · 04 Aug, 2026
Heap patterns in Java: the size-k trick for top-k, two heaps for a running median, and why a priority queue beats sorting when you only need the extreme.
Coding Interview
Jason Yang · 04 Aug, 2026
Stacks do two interview jobs in Java: matching what you must resolve later (parentheses, RPN), and the monotonic stack that finds next-greater in one O(n) pass.
Coding Interview
Jason Yang · 04 Aug, 2026
House Robber II (LeetCode 213): the circular twist solved by running the linear House Robber twice — once excluding the first house, once the last — in Java.
Coding Interview
Jason Yang · 04 Aug, 2026
House Robber (LeetCode 198): the take-or-skip recurrence, why you can't rob adjacent houses, and the O(1)-space rolling solution in Java.
