Greedy

LeetCode 3796 note: each position’s bound is the min of its own limit, the left bound + difference and the right bound + difference; one pass each way

LeetCode 3689 note: the same subarray may be chosen repeatedly, and the whole array’s max minus min is the best single value, so choose it k times

LeetCode 2294 note: subsequences ignore order, so sort and extend each group from its minimum until a value exceeds min + k

LeetCode 2131 note: pair each word with its reverse on both sides; self-palindromes also pair with each other, and only one leftover can sit in the middle

Solving the Car Fleet problem using stack-based approach

LeetCode 135 note: one pass left to right for the left neighbor, one right to left for the right neighbor, and give each child the larger of the two

LeetCode 3638 note: greedily cut a segment as soon as a value below its maximum appears; until then the segment is non-decreasing, so its maximum is the previous value

LeetCode 3627 note: after sorting, each group takes the two largest and the smallest, with the second largest as the median; the answer takes every other value from the end, n / 3 of them

LeetCode 2745 note: AA and BB must alternate, using min(x, y) pairs plus one extra of the more common kind, and every AB fits in

LeetCode 2410 note: sort both sides, then same-direction pointers match the weakest player with the smallest trainer that is good enough

LeetCode 1353 note: each day, attend the event that ends earliest, using a min-heap of end days

LeetCode 3572 note: keep the largest y for each x, then take the three largest