feat: 2024 day 20

Author: Programator2

2024/20a.py

@@ -0,0 +1,57 @@
+from aoc import *
+import sys
+
+
+DIRS = ((-1, 0), (0, 1), (1, 0), (0, -1))
+
+
+def search(i, j, m, lengths, length):
+    """
+    :param lengths: lengths from the end
+    """
+    togo = []
+    for d in DIRS:
+        pos = i + d[0], j + d[1]
+        if (
+            pos in m
+            and m[pos] in '.SE'
+            and (pos not in lengths or lengths[pos] > length + 1)
+        ):
+            lengths[pos] = length + 1
+            togo.append(pos)
+    for pos in togo:
+        search(*pos, m, lengths, length + 1)
+
+
+def main(infi: str):
+    sys.setrecursionlimit(10000)
+    inp = load_map_dd(infi)
+    end = [(i, j) for (i, j), e in inp.items() if e == 'E'][0]
+    lengths = {}
+    search(*end, inp, lengths, 0)
+    s = 0
+    for (i, j), e in inp.items():
+        if e == '#':
+            connected = [
+                (i + d[0], j + d[1])
+                for d in DIRS
+                if (i + d[0], j + d[1]) in inp
+                and inp[i + d[0], j + d[1]] in '.SE'
+            ]
+            if len(connected) == 2:
+                length = abs(lengths[connected[0]] - lengths[connected[1]]) - 2
+                if length >= 100:
+                    s += 1
+            elif len(connected) > 2:
+                continue
+    return s
+
+
+DAY = 20
+FILE_TEST = f"{DAY}_testa.txt"
+# FILE_TEST = f"{DAY}_testb.txt"
+FILE_EXP = f"{DAY}_exp.txt"
+FILE = f"{DAY}.txt"
+# test_and_submit(main, FILE_TEST, FILE_EXP, FILE, DAY)
+# print(main(FILE_TEST))
+print(main(FILE))

2024/20b.py

@@ -0,0 +1,75 @@
+from aoc import *
+import sys
+
+
+DIRS = ((-1, 0), (0, 1), (1, 0), (0, -1))
+
+
+def search(i, j, m, lengths, length):
+    """
+    :param lengths: lengths from the end
+    """
+    togo = []
+    for d in DIRS:
+        pos = i + d[0], j + d[1]
+        if (
+            pos in m
+            and m[pos] in '.SE'
+            and (pos not in lengths or lengths[pos] > length + 1)
+        ):
+            lengths[pos] = length + 1
+            togo.append(pos)
+    for pos in togo:
+        search(*pos, m, lengths, length + 1)
+
+
+def generate_distances():
+    diffs = set()
+    for i in range(2, 21):
+        for a in range(i):
+            b = i - a
+            diffs.update(
+                {
+                    (a, b),
+                    (a, -b),
+                    (-a, b),
+                    (-a, -b),
+                    (b, a),
+                    (b, -a),
+                    (-b, a),
+                    (-b, -a),
+                }
+            )
+    return diffs
+
+
+def main(infi: str):
+    sys.setrecursionlimit(10000)
+    inp = load_map_dd(infi)
+    end = [(i, j) for (i, j), e in inp.items() if e == 'E'][0]
+    lengths = {}
+    search(*end, inp, lengths, 0)
+    distances = generate_distances()
+    s = 0
+    for (i, j), e in inp.items():
+        if e in '.SE':
+            for a, b in distances:
+                if inp.get((i + a, j + b), None) in ['.', 'E', 'S']:
+                    length = (
+                        lengths[i + a, j + b]
+                        - lengths[i, j]
+                        - (abs(a) + abs(b))
+                    )
+                    if length >= 100:
+                        s += 1
+    return s
+
+
+DAY = 20
+FILE_TEST = f"{DAY}_testa.txt"
+# FILE_TEST = f"{DAY}_testb.txt"
+FILE_EXP = f"{DAY}_exp.txt"
+FILE = f"{DAY}.txt"
+# test_and_submit(main, FILE_TEST, FILE_EXP, FILE, DAY)
+# print(main(FILE_TEST))
+print(main(FILE))

README.org

@@ -9,6 +9,7 @@
 |  23 | 00:24:26 |  2632 |     0 | 01:09:24 |  2938 |     0 |
 |  22 | 00:07:06 |   766 |     0 | 05:23:29 |  7143 |     0 |
 |  21 |     >24h | 15115 |     0 |     >24h | 11364 |     0 |
+|  20 | 02:16:45 |  5713 |     0 |     >24h | 20970 |     0 |
 |  19 | 01:44:22 |  6641 |     0 | 01:50:06 |  5444 |     0 |
 |  17 | 00:27:08 |  1748 |     0 | 07:06:10 |  5688 |     0 |
 |  15 | 00:32:17 |  2397 |     0 | 02:59:49 |  4379 |     0 |