2024.06

challenges/2024/06-guardGallivant/README.md

@@ -0,0 +1,5 @@
+# [Day 6: Guard Gallivant](https://adventofcode.com/2024/day/6)
+
+Part 2 is:
+* higher than 456
+* less than 1689

challenges/2024/06-guardGallivant/main.py

@@ -0,0 +1,84 @@
+import sys
+from gridutil import grid, coord
+from typing import Optional
+from tqdm import tqdm
+
+
+def parse(instr: str) -> grid.Grid:
+    return grid.parse(instr)
+
+
+def find_start(g: grid.Grid) -> coord.Coordinate:
+    for pos in g:
+        if g[pos] == "^":
+            return pos
+    assert False, "no start point found"
+    
+    
+def modplus(x: int) -> int:
+    return (x + 1) % 4
+
+    
+dirs = [coord.Direction.Up, coord.Direction.Right, coord.Direction.Down, coord.Direction.Left]
+
+
+class LoopEncounteredException(Exception):
+    pass
+
+
+def trace(g: grid.Grid, guard_pos: coord.Coordinate, guard_direction: int) -> set[tuple[coord.Coordinate, int]]:
+    visited_sequence = set()
+    
+    while guard_pos in g:
+        if (guard_pos, guard_direction) in visited_sequence:
+            raise LoopEncounteredException
+        
+        visited_sequence.add((guard_pos, guard_direction))
+        
+        nc = coord.add(guard_pos, dirs[guard_direction % 4].delta())
+        if nc in g and g[nc] == "#":
+            guard_direction = modplus(guard_direction)
+        else:
+            guard_pos = nc
+
+    return visited_sequence
+
+
+def one(instr: str) -> int:
+    g = parse(instr)
+    return len(set(map(lambda x: x[0], trace(g, find_start(g), 0))))
+
+
+def two(instr: str) -> int:
+    g = parse(instr)
+    
+    start_pos = find_start(g)
+    seq = trace(g, start_pos, 0)
+    known_blocks = set()
+    
+    for (pos, _) in tqdm(seq, file=sys.stderr):
+        assert pos in g, "pos off the rails"
+        g[pos] = "#"
+        try:
+            trace(g, start_pos, 0)
+        except LoopEncounteredException:
+            known_blocks.add(pos)
+        g[pos] = "."
+    
+    return len(known_blocks)
+
+
+def _debug(*args, **kwargs):
+    kwargs["file"] = sys.stderr
+    print(*args, **kwargs)
+
+
+if __name__ == "__main__":
+    if len(sys.argv) < 2 or sys.argv[1] not in ["1", "2"]:
+        print("Missing day argument", file=sys.stderr)
+        sys.exit(1)
+    inp = sys.stdin.read().strip()
+    if sys.argv[1] == "1":
+        print(one(inp))
+    else:
+        print(two(inp))

challenges/2024/06-guardGallivant/sample.txt

@@ -0,0 +1,10 @@
+....#.....
+.........#
+..........
+..#.......
+.......#..
+..........
+.#..^.....
+........#.
+#.........
+......#...

challenges/2024/06-guardGallivant/tests.json

@@ -0,0 +1,14 @@
+{
+    "1": [
+        {
+            "is": "41",
+            "input": "....#.....\n.........#\n..........\n..#.......\n.......#..\n..........\n.#..^.....\n........#.\n#.........\n......#...\n\n"
+        }
+    ],
+    "2": [
+        {
+            "is": "6",
+            "input": "....#.....\n.........#\n..........\n..#.......\n.......#..\n..........\n.#..^.....\n........#.\n#.........\n......#...\n"
+        }
+    ]
+}

challenges/2024/README.md

@@ -4,7 +4,7 @@ Solutions to the [2024 Advent of Code](https://adventofcode.com/2024)!
 
 ---
 
-Total stars: **10 ★**
+Total stars: **12 ★**
 
 ![Benchmark graph](./benchmark-graph.png)
 
@@ -18,4 +18,5 @@ A day denoted with an asterisk means it has a visualisation.
 | 02 - Red-Nosed Reindeer             | ★ ★   | Python               ||
 | 03 - Mull It Over                   | ★ ★   | Python               | The first instance of Advent of Parsing this year! |
 | 04* - Ceres Search                  | ★ ★   | Python               | When it says a cross, it does not mean a plus. |
-| 05 - Print Queue                    | ★ ★   | Python               | Before you dismiss and idea as being "too simple", make sure you check that it doesn't work. |
+| 05 - Print Queue                    | ★ ★   | Python               | Before you dismiss and idea as being "too simple", make sure you check that it doesn't work. |
+| 06 - Guard Gallivant                | ★ ★   | Python               | oh dear runtime (also I knew what I wanted to do for so long it just took me 3 hours to implement it properly) |

challenges/2024/benchmarks.jsonl

@@ -8,3 +8,5 @@
 {"day": 4, "part": 2, "runner": "py", "min": 0.05280470848083496, "max": 0.06299543380737305, "avg": 0.05627016305923462, "n": 100}
 {"day": 5, "part": 1, "runner": "py", "min": 0.02001357078552246, "max": 0.030559301376342773, "avg": 0.02152919292449951, "n": 100}
 {"day": 5, "part": 2, "runner": "py", "min": 0.02507805824279785, "max": 0.03197765350341797, "avg": 0.027084295749664308, "n": 100}
+{"day": 6, "part": 1, "runner": "py", "min": 0.0671079158782959, "max": 0.0671079158782959, "avg": 0.0671079158782959, "n": 1}
+{"day": 6, "part": 2, "runner": "py", "min": 61.63975167274475, "max": 61.63975167274475, "avg": 61.63975167274475, "n": 1}