Module day08

Treetop Tree House

Part 1 is solved with an efficient O(n) algorithm. Part 2 is also solved with an efficient O(n) algorithm, using a bit manipulation trick to make the complexity independent of the number of digits.

Constants

MASK 🔒

ONES 🔒

Functions

parse

Convert a 2D grid of ASCII digits into a 1D vec of heights.

part1

Calculate visible trees using a rolling maximum for each row and column in left, right, up and down directions.

part2

Calculate the distance visible in each direction by using 10 rolling maximum values for each height packed into a single u64.

Type Aliases

Input 🔒