The input consists of (typically) 2000 3-to-4-digit numbers, roughly (but not strictly) ordered by value.
Part 1 asks how many numbers were actually greater than their predecessors.
Part 2 asks the same, but not on the numbers themselves, but a three-number sliding average,
A simple first puzzle. The low-pass filter for part 2 can be either implemented as an intermediate processing step, or directly while comparing (by having a four-element sliding window instead of just three elements), which leads to shorter code.
- Part 1, Python: 68 bytes, <100 ms
- Part 2, Python: 92 bytes, <100 ms