jcreek/advent-of-code
1
0
Fork 0
mirror of https://github.com/jcreek/advent-of-code.git synced 2026-07-13 03:03:46 +00:00
Code Issues Packages Projects Releases Wiki Activity

feat(*): Add 2021-09 files (part 1 working, part 2 not)

Browse Source
This commit is contained in:
Josh Creek
2021-12-09 17:26:21 +00:00
parent 2e70f9e457
commit c16b1f3fc2
5 changed files with 312 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files
2021/09/TaskPart2.txt
+38
View File
@@ -0,0 +1,38 @@
--- Part Two ---
Next, you need to find the largest basins so you know what areas are most important to avoid.
A basin is all locations that eventually flow downward to a single low point. Therefore, every low point has a basin, although some basins are very small. Locations of height 9 do not count as being in any basin, and all other locations will always be part of exactly one basin.
The size of a basin is the number of locations within the basin, including the low point. The example above has four basins.
The top-left basin, size 3:
2199943210
3987894921
9856789892
8767896789
9899965678
The top-right basin, size 9:
2199943210
3987894921
9856789892
8767896789
9899965678
The middle basin, size 14:
2199943210
3987894921
9856789892
8767896789
9899965678
The bottom-right basin, size 9:
2199943210
3987894921
9856789892
8767896789
9899965678
Find the three largest basins and multiply their sizes together. In the above example, this is 9 * 14 * 9 = 1134.
What do you get if you multiply together the sizes of the three largest basins?