Array

LeetCode 3708 note: lengths 1 and 2 always work; from the third element, extend while nums[i] == nums[i-1] + nums[i-2], otherwise reset to 2

LeetCode 3701 note: add even indices and subtract odd ones; with slices, sum(nums[::2]) - sum(nums[1::2])

LeetCode 3697 note: each non-zero digit times its place value is one component; output them from the highest place down

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 3688 note: OR only the even numbers; the starting value 0 is also the answer when there are none

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

LeetCode 1493 note: find the longest window with at most one 0; since one element must be deleted, the answer is the window length minus 1

LeetCode 3195 note: track the topmost, bottommost, leftmost and rightmost 1; the area is height times width

LeetCode 3649 note: simplify the condition to “larger absolute value <= 2 × smaller absolute value”, then count with two pointers over sorted absolute values

Solving the Car Fleet problem using stack-based approach

Solving the Largest Rectangle in Histogram problem using monotonic stack approach

Solving the Daily Temperatures problem using monotonic stack approach