Binary-Search

LeetCode 1712 note: fix the first cut and find the valid range of the second cut with two bisects or two monotonic pointers

LeetCode 825 note: after sorting, the people someone can invite have ages in (0.5 × age + 7, age], a contiguous range kept with two same-direction pointers, minus the person themself

LeetCode 3814 note: sort by cost with a prefix maximum of capacity, and bisect the most expensive partner for each machine

LeetCode 2968 note: after sorting, the cheapest common target for a block is its median; prefix sums give the cost in O(1), and it grows with the window, so slide

LeetCode 2302 note: score = sum × length with positive numbers grows with the window; shrink while the score is >= k, and right - left + 1 valid subarrays end at right

LeetCode 3413 note: the best k bags always have one end on a segment boundary; compute “left end at a segment start” and “right end at a segment end” (the latter by mirroring and reusing the same function)

LeetCode 2009 note: the result is n consecutive integers; after deduplicating and sorting, a sliding window finds the most distinct values within a span of n - 1, and the rest must change

LeetCode 2555 note: a sliding window gives how many prizes a segment ending at each prize collects, and a running “best single segment among the first i prizes” supplies the second segment to its left

LeetCode 2106 note: the harvest is always a contiguous block of fruits; covering [L, R] takes (R - L) + min(|start - L|, |R - start|) steps, so slide a window over the fruits array

LeetCode 2831 note: list the positions of each value and slide a window over that list; the deletions needed are the span of positions minus the number of copies

LeetCode 2779 note: each number can become anything in [x - k, x + k], so a group can become one value ⇔ max - min <= 2k; sort and find the longest such window

LeetCode 2271 note: starting the carpet at some segment’s start is never worse; after sorting, two pointers sum the fully covered segments and count the last one partially