1582 articles
LeetCode 4 is the most famous FAANG hard problem. Solve the median of two sorted arrays in O(log(min(m,n))) by binary searching for the correct partition position.
LeetCode 315 is a Google and Amazon classic. Count how many elements to the right are smaller than each element using merge sort with index tracking or a Fenwick Tree, both running in O(n log n).
LeetCode 354 reduces a 2D nesting problem to 1D Longest Increasing Subsequence with patience sorting, giving an O(n log n) FAANG-friendly solution.
LeetCode 2439 minimizes the array maximum by transferring values right-to-left. Solve it with binary search on the answer or, more elegantly, with the prefix-average closed form.
LeetCode 1891 finds the maximum ribbon length such that we can cut at least k pieces. A clean O(n log max) binary-search-on-answer template every interviewer expects.