AoC 2024: Day 10

tobiasvl · tobiasvl · commit 88e0cf8874b5 · 2024-12-10T10:38:15.000+01:00
diff --git a/2024/day10/day10.py b/2024/day10/day10.py
@@ -0,0 +1,50 @@
+#!/usr/bin/python3
+
+# Override lists and strings so negative indices don't wrap around
+class gridlist(list):
+    def __getitem__(self, n):
+        if n < 0:
+            raise IndexError("Negative index")
+        return list.__getitem__(self, n)
+
+transforms = [
+    (0, -1),
+    (1, 0),
+    (0, 1),
+    (-1, 0)
+]
+
+def adjacent(location):
+    return [(location[0] + direction[0], location[1] + direction[1]) for direction in transforms]
+
+def main():
+    with open('input') as f:
+        grid = gridlist([gridlist([int(a) for a in line.strip()]) for line in f.readlines()])
+
+    trailheads = list()
+    for y in range(len(grid)):
+        for x in range(len(grid[y])):
+            if grid[y][x] == 0:
+                trailheads.append((y,x))
+
+    def find(location, seen=None):
+        if grid[location[0]][location[1]] == 9:
+            if seen != None:
+                if location in seen:
+                    return 0
+                seen.add(location)
+            return 1
+        score = 0
+        for new_location in adjacent(location):
+            try:
+                if grid[new_location[0]][new_location[1]] == grid[location[0]][location[1]] + 1:
+                    score += find(new_location, seen)
+            except IndexError:
+                pass
+        return score
+
+    print(sum([find(location, set()) for location in trailheads]))
+    print(sum([find(location) for location in trailheads]))
+
+if __name__ == "__main__":
+    main()
diff --git a/README.md b/README.md
@@ -1,6 +1,6 @@
 # Advent of Code
 
-![](https://img.shields.io/badge/2024%20⭐-9-yellow) ![](https://img.shields.io/badge/2022%20⭐-6-yellow) ![](https://img.shields.io/badge/2021%20⭐-23-yellow) ![](https://img.shields.io/badge/2020%20⭐-16-yellow) ![](https://img.shields.io/badge/2019%20⭐-1-yellow) ![](https://img.shields.io/badge/2018%20⭐-41-yellow) ![](https://img.shields.io/badge/2017%20⭐-50-yellow) ![](https://img.shields.io/badge/2016%20⭐-42-yellow) ![](https://img.shields.io/badge/2015%20⭐-12-yellow) 
+![](https://img.shields.io/badge/2024%20⭐-10-yellow) ![](https://img.shields.io/badge/2022%20⭐-6-yellow) ![](https://img.shields.io/badge/2021%20⭐-23-yellow) ![](https://img.shields.io/badge/2020%20⭐-16-yellow) ![](https://img.shields.io/badge/2019%20⭐-1-yellow) ![](https://img.shields.io/badge/2018%20⭐-41-yellow) ![](https://img.shields.io/badge/2017%20⭐-50-yellow) ![](https://img.shields.io/badge/2016%20⭐-42-yellow) ![](https://img.shields.io/badge/2015%20⭐-12-yellow) 
 
 [My](https://github.com/tobiasvl) solutions for the puzzles of [Advent of Code](http://adventofcode.com).
 
