Hot100: Maximum Subarray (Kadane O(n) ACERS Guide)

Subtitle / Summary Maximum Subarray is the classic 1D DP / greedy template. This ACERS guide explains Kadane’s idea, engineering use cases, and runnable multi-language solutions. Reading time: 10–12 min Tags: Hot100, dynamic programming, greedy SEO keywords: Maximum Subarray, Kadane, dynamic programming, O(n), Hot100 Meta description: Kadane O(n) maximum subarray sum with engineering scenarios and multi-language code. Target Readers Hot100 learners building stable templates Engineers analyzing peak segments in time series Anyone who wants a clean O(n) solution Background / Motivation Maximum subarray sum appears in P&L streaks, KPI lift windows, anomaly bursts, and throughput gains. The naive O(n^2) enumeration does not scale. Kadane’s algorithm solves it in one pass. ...

January 23, 2026 · 7 min · map[name:Jeanphilo]

LeetCode 1437: Check If All 1's Are at Least K Apart (ACERS Guide)

Subtitle / Summary A classic event-spacing validation model. This ACERS guide explains the one-pass logic, engineering use cases, and runnable multi-language solutions. Reading time: 10–12 min Tags: array, two pointers, event spacing SEO keywords: LeetCode 1437, event spacing, O(n) Meta description: One-pass validation for minimum spacing between 1s, with engineering use cases and multi-language code. Target Readers LeetCode learners building stable templates Engineers working on monitoring / risk control / behavior analytics Developers who need spacing or rate-limit validations Background / Motivation Many systems require events to be spaced apart: login failures, alarms, sensitive actions, API calls, etc. This problem maps directly to event spacing validation. A one-pass, O(1)-memory solution is ideal for real-time systems. ...

January 22, 2026 · 7 min · map[name:Jeanphilo]