Sliding-Window

LeetCode 2516 note: taking from both ends leaves a middle block in which each letter may appear at most total − k times; 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

LeetCode 1838 note: after sorting, raising the whole window to nums[right] costs nums[right] × length − window sum; shrink the left while that exceeds k

LeetCode 3634 note: after sorting, what remains is always a contiguous block; for each minimum nums[left], a right-only pointer finds how far it can extend, and everything outside is removed

LeetCode 3090 note: a longest-window slide that shrinks the left whenever the newly added character appears more than twice

LeetCode 2958 note: a longest-window slide that shrinks the left whenever the newly added number appears more than k times

LeetCode 220 note: with bucket size valueDiff + 1, two numbers in one bucket always qualify, so only the two neighboring buckets need checking; the window keeps the latest indexDiff numbers, so each bucket holds at most one

LeetCode 2024 note: a window is valid when the rarer of T and F appears at most k times (flip all of them); shrink the left when it is not

LeetCode 1208 note: each position costs |s[i] - t[i]|, so the problem becomes the longest subarray with sum <= maxCost

LeetCode 2953 note: split where neighboring letters differ by more than 2; in each segment enumerate the number of distinct letters d, slide a fixed window of d × k, and track how many letters appear exactly k times

LeetCode 2269 note: convert the number to a string and check every length-k substring; 0 cannot be a divisor

LeetCode 2156 note: the first character has weight p^0, so sliding right to left needs only multiply by p, add the new character, and subtract the outgoing one times p^k; the modulus may not be prime, so no modular inverse