Easy

LeetCode 2540 note: one pointer per sorted array, advance the smaller side, and the first match is the answer

LeetCode 976 note: after sorting, check consecutive triples from the largest down; the first with a + b > c gives the largest perimeter

LeetCode 3684 note: all values are positive, so deduplicate and take the k largest in descending order

LeetCode 2273 note: repeatedly deleting a word that is an anagram of the previous one keeps exactly the words that are not anagrams of the last kept word; compare sorted strings

LeetCode 1984 note: after sorting, the chosen k scores are always contiguous; slide a fixed window of length k and subtract its ends

LeetCode 2697 note: converging pointers, setting both ends to the smaller character whenever they differ

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 1763 note: a character whose other case never appears cannot be in the answer, so split on it and recurse, preferring the left side on ties

LeetCode 3803 note: add characters to a set while scanning; count a prefix when its distinct count equals its length % 3

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

LeetCode 3798 note: parity depends only on the last digit, so just delete trailing 1s; keeping more digits is larger