Day 10

Author: ryanmalonzo

README.md

@@ -37,7 +37,7 @@ In accordance with the rules of this event, my input files (`input.txt`) are not
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-| 10  | ⏳     | ⏳     |
+| 10  | ✅     | ✅     |
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@@ -70,7 +70,7 @@ In accordance with the rules of this event, my input files (`input.txt`) are not
 | 7   | `itertools.product` to get all possible operator combinations                                                 | Only a 3-line difference                                                 |
 | 8   | `itertools.combinations` to get all possible _antenna_ pairs                                                  |                                                                          |
 | 9   |                                                                                                               | Heaps with `heapq` to keep a sorted list of free space indices by length |
-| 10  |                                                                                                               |                                                                          |
+| 10  | Recursion                                                                                                     | Accidentally wrote the code for it while trying to do part 1             |
 | 11  |                                                                                                               |                                                                          |
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 | 13  |                                                                                                               |                                                                          |

day_10/part_1.py

@@ -0,0 +1,58 @@
+def parse_input():
+    INPUT = "input.txt"
+    with open(INPUT) as file:
+        arr = []
+        t = []
+        for i, line in enumerate(file.read().splitlines()):
+            curr = [int(c) for c in line]
+            arr.append(curr)
+            for j, c in enumerate(curr):
+                if c == 0:
+                    t.append((i, j))
+        return arr, t
+
+
+def scan(
+    topographic_map: list[list[int]],
+    x: int,
+    y: int,
+    height: int,
+    reached: set[tuple[int, int]],
+) -> None:
+    if height == 9:
+        reached.add((x, y))
+
+    bounds = []
+    for z, a in [(x + 1, y), (x, y + 1), (x - 1, y), (x, y - 1)]:
+        if (
+            z >= 0
+            and a >= 0
+            and z < len(topographic_map)
+            and a < len(topographic_map[0])
+            and topographic_map[z][a] == height + 1
+        ):
+            bounds.append((z, a))
+
+    if not len(bounds):
+        return
+
+    for z, a in bounds:
+        scan(topographic_map, z, a, height + 1, reached)
+
+
+def solve():
+    topographic_map, trailheads = parse_input()
+    sum_scores = 0
+    for x, y in trailheads:
+        reached: set[tuple[int, int]] = set()
+        scan(topographic_map, x, y, 0, reached)
+        sum_scores += len(reached)
+    print(sum_scores)
+
+
+if __name__ == "__main__":
+    import time
+
+    start_time = time.time()
+    solve()
+    print("--- %s seconds ---" % (time.time() - start_time))

day_10/part_2.py

@@ -0,0 +1,52 @@
+def parse_input():
+    INPUT = "input.txt"
+    with open(INPUT) as file:
+        arr = []
+        t = []
+        for i, line in enumerate(file.read().splitlines()):
+            curr = [int(c) for c in line]
+            arr.append(curr)
+            for j, c in enumerate(curr):
+                if c == 0:
+                    t.append((i, j))
+        return arr, t
+
+
+def scan(topographic_map: list[list[int]], x: int, y: int, height: int) -> int:
+    if height == 9:
+        return 1
+
+    bounds = []
+    for z, a in [(x + 1, y), (x, y + 1), (x - 1, y), (x, y - 1)]:
+        if (
+            z >= 0
+            and a >= 0
+            and z < len(topographic_map)
+            and a < len(topographic_map[0])
+            and topographic_map[z][a] == height + 1
+        ):
+            bounds.append((z, a))
+
+    if not len(bounds):
+        return 0
+
+    s = 0
+    for z, a in bounds:
+        s += scan(topographic_map, z, a, height + 1)
+    return s
+
+
+def solve():
+    topographic_map, trailheads = parse_input()
+    sum_ratings = 0
+    for x, y in trailheads:
+        sum_ratings += scan(topographic_map, x, y, 0)
+    print(sum_ratings)
+
+
+if __name__ == "__main__":
+    import time
+
+    start_time = time.time()
+    solve()
+    print("--- %s seconds ---" % (time.time() - start_time))

template.py

@@ -0,0 +1,16 @@
+def parse_input():
+    INPUT = "input.txt"
+    with open(INPUT) as file:
+        pass
+
+
+def solve():
+    pass
+
+
+if __name__ == "__main__":
+    import time
+
+    start_time = time.time()
+    solve()
+    print("--- %s seconds ---" % (time.time() - start_time))