LeetCode

LeetCode 3325 note: an “at least one character appears k times” counting window; when the new character reaches k, keep shrinking until it drops to k - 1

LeetCode 2962 note: an “at least k” counting window: keep shrinking while the max appears k times, after which every left end in [0, left) is valid, so count += left

LeetCode 2762 note: a sliding window with two monotonic queues for the window maximum and minimum

LeetCode 1358 note: an “at least one each of a, b, c” counting window: keep shrinking while all three are present, then count += left

LeetCode 632 note: a heap of each list’s current element plus the running maximum; always advance the smallest

LeetCode 3816 note: a monotonic stack that deletes a larger top while another copy exists, then trims duplicate letters off the end since a prefix is always smaller

LeetCode 3815 note: one max-heap per item, push a new entry on every bid change, and drop stale entries on query

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

LeetCode 3813 note: count letters only, split into vowels and consonants; the score is 0 with no consonants, otherwise integer division

LeetCode 3258 note: valid means zeros <= k or ones <= k; it is invalid only when both exceed k, and after shrinking there are right - left + 1 valid substrings ending at right

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 2904 note: with exactly k ones in the window, also shrink away leading zeros to get the shortest beautiful substring ending at right; compare by length first, then lexicographically