add day 10

day10/code.py

@@ -0,0 +1,69 @@
+import sys
+sys.path.append('../aoclib')
+
+from aoclib import Input
+
+def find_starting_points(field) -> list[tuple[int, int]]:
+    points = []
+    for y in range(len(field)):
+        for x in range(len(field[0])):
+            if field[y][x] == 0:
+                points.append((x, y))
+    return points
+
+
+def num_trails(point: tuple[int, int], curr: int, field: list[list[int]]) -> list[tuple[int, int]]:
+    if out_of_bounds(point, field):
+        return [None]
+    
+    x, y = point
+    if field[y][x] != curr:
+        # impossible path
+        return [None]
+
+    if curr == 9 and field[y][x] == curr:
+        # goal
+        return [point]
+
+    curr += 1
+
+    opts = list()
+
+    opts.extend(num_trails((x+1, y), curr, field))
+    opts.extend(num_trails((x-1, y), curr, field))
+    opts.extend(num_trails((x, y+1), curr, field))
+    opts.extend(num_trails((x, y-1), curr, field))
+    
+    return opts
+
+
+def out_of_bounds(point: tuple[int, int], field: list[list[int]]) -> bool:
+    x, y = point
+    return y < 0 or y >= len(field) or x < 0 or x >= len(field[0])
+
+
+def solve1(field: list[list[int]]) -> int:
+    starts = find_starting_points(field)
+    count = 0
+    for p in starts:
+        trails = num_trails(p, 0, field)
+        count += sum([1 if n else 0 for n in set(trails)])
+    return count
+
+def solve2(field: list[list[int]]) -> int:
+    starts = find_starting_points(field)
+    count = 0
+    for p in starts:
+        trails = num_trails(p, 0, field)
+        count += sum([1 if n else 0 for n in trails])
+    return count
+
+if __name__ == '__main__':
+    #field = Input('input_test.txt').lines_split_as_ints()
+    field = Input('input.txt').lines_split_as_ints()
+
+    #part 1
+    print('part 1:', solve1(field)) # 733
+
+    #part 2
+    print('part 2:', solve2(field)) # 1514