Array on Jeanphilo Bloghttps://shio-chan-dev.github.io/jeanblog/tags/array/Recent content in Array on Jeanphilo BlogHugo -- 0.159.2en-usTue, 10 Feb 2026 10:25:53 +0800Hot100: First Missing Positive In-Place Index Placement ACERS Guidehttps://shio-chan-dev.github.io/jeanblog/alg/leetcode/hot100/41-first-missing-positive/Tue, 10 Feb 2026 10:25:53 +0800https://shio-chan-dev.github.io/jeanblog/alg/leetcode/hot100/41-first-missing-positive/Find the first missing positive in O(n) time and O(1) extra space using in-place index placement (value x should be placed at index x-1), with engineering mapping, pitfalls, and runnable multi-language implementations.Hot100: Spiral Matrix (Boundary Shrinking Simulation ACERS Guide)https://shio-chan-dev.github.io/jeanblog/alg/leetcode/hot100/54-spiral-matrix/Tue, 03 Feb 2026 10:01:50 +0800https://shio-chan-dev.github.io/jeanblog/alg/leetcode/hot100/54-spiral-matrix/Traverse a matrix in clockwise spiral order in O(mn) using boundary shrinking. Includes engineering scenarios, pitfalls, and multi-language implementations.Hot100: Trapping Rain Water (Two Pointers O(n) ACERS Guide)https://shio-chan-dev.github.io/jeanblog/alg/leetcode/hot100/42-trapping-rain-water/Sat, 24 Jan 2026 10:40:53 +0800https://shio-chan-dev.github.io/jeanblog/alg/leetcode/hot100/42-trapping-rain-water/Compute trapped rain water in O(n) using two pointers and left/right maxima. Includes engineering scenarios, pitfalls, and multi-language implementations.LeetCode 1437: Check If All 1's Are at Least K Apart (ACERS Guide)https://shio-chan-dev.github.io/jeanblog/alg/leetcode/1437-check-if-all-ones-are-at-least-k-places-away/Thu, 22 Jan 2026 10:49:42 +0800https://shio-chan-dev.github.io/jeanblog/alg/leetcode/1437-check-if-all-ones-are-at-least-k-places-away/One-pass check to ensure all 1s are at least k apart. Includes engineering scenarios, pitfalls, and multi-language implementations.LeetCode 239: Sliding Window Maximum (Monotonic Queue ACERS Guide)https://shio-chan-dev.github.io/jeanblog/alg/leetcode/239-sliding-window-maximum/Mon, 19 Jan 2026 17:46:14 +0800https://shio-chan-dev.github.io/jeanblog/alg/leetcode/239-sliding-window-maximum/Solve Sliding Window Maximum in O(n) with a monotonic queue, including engineering scenarios, complexity comparisons, and multi-language implementations.LeetCode 1512: Number of Good Pairs (Hash Counting ACERS Guide)https://shio-chan-dev.github.io/jeanblog/alg/leetcode/1512-number-of-good-pairs/Tue, 30 Dec 2025 11:40:00 +0800https://shio-chan-dev.github.io/jeanblog/alg/leetcode/1512-number-of-good-pairs/Solve Good Pairs with one-pass hash counting, plus engineering scenarios, complexity, and multi-language solutions.