1582 articles
LeetCode 167 Two Sum II is asked at Amazon, Microsoft, Google, and Bloomberg. Solve it in O(n) time and O(1) space with the inward two-pointer technique on a sorted array.
LeetCode 713 Subarray Product Less Than K is asked at Google, Amazon, and Stripe. Count contiguous subarrays in O(n) using a multiplicative sliding window.
LeetCode 1423 Maximum Points You Can Obtain from Cards is asked at Google, Amazon, and Meta. Convert pick-from-ends into a fixed-size minimum-window problem in O(n).
LeetCode 1248 Count Number of Nice Subarrays is asked at Google and Amazon. Convert "exactly k odds" into atMost(k) minus atMost(k-1) for an O(n) solution.
LeetCode 930 Binary Subarrays With Sum is asked at Google, Amazon, and Meta. Count subarrays with exact sum in O(n) using atMost(goal) minus atMost(goal-1).