day5 part 1

day5/README.md

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+# Day 5: Supply Stacks
+
+The expedition can depart as soon as the final supplies have been unloaded from the ships. Supplies are stored in stacks
+of marked **crates**, but because the needed supplies are buried under many other crates, the crates need to be
+rearranged.
+
+The ship has a **giant cargo crane** capable of moving crates between stacks. To ensure none of the crates get crushed
+or fall over, the crane operator will rearrange them in a series of carefully-planned steps. After the crates are
+rearranged, the desired crates will be at the top of each stack.
+
+The Elves don't want to interrupt the crane operator during this delicate procedure, but they forgot to ask her which
+crate will end up where, and they want to be ready to unload them as soon as possible, so they can embark.
+
+They do, however, have a drawing of the starting stacks of crates and the rearrangement procedure (your puzzle input).
+For example:
+
+```
+    [D]    
+[N] [C]    
+[Z] [M] [P]
+ 1   2   3 
+
+move 1 from 2 to 1
+move 3 from 1 to 3
+move 2 from 2 to 1
+move 1 from 1 to 2
+```
+
+In this example, there are three stacks of crates. Stack 1 contains two crates: crate `Z` is on the bottom, and
+crate `N` is on top. Stack 2 contains three crates; from bottom to top, they are crates `M`, `C`, and `D`. Finally,
+stack 3 contains a single crate, `P`.
+
+Then, the rearrangement procedure is given. In each step of the procedure, a quantity of crates is moved from one stack
+to a different stack. In the first step of the above rearrangement procedure, one crate is moved from stack 2 to stack
+1, resulting in this configuration:
+
+```
+[D]        
+[N] [C]    
+[Z] [M] [P]
+ 1   2   3 
+```
+
+In the second step, three crates are moved from stack 1 to stack 3. Crates are moved **one at a time**, so the first
+crate to be moved (`D`) ends up below the second and third crates:
+
+```
+        [Z]
+        [N]
+    [C] [D]
+    [M] [P]
+ 1   2   3 
+```
+
+Then, both crates are moved from stack 2 to stack 1. Again, because crates are **moved one at a time**, crate `C` ends
+up below crate `M`:
+
+```
+        [Z]
+        [N]
+[M]     [D]
+[C]     [P]
+ 1   2   3 
+```
+
+Finally, one crate is moved from stack 1 to stack 2:
+
+```
+        [Z]
+        [N]
+        [D]
+[C] [M] [P]
+ 1   2   3 
+```
+
+The Elves just need to know **which crate will end up on top of each stack**; in this example, the top crates are `C` in
+stack 1, `M` in stack 2, and `Z` in stack 3, so you should combine these together and give the Elves the message `CMZ`.
+
+**After the rearrangement procedure completes, what crate ends up on top of each stack?**

day5/input.txt

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+[V]     [B]                     [C]
+[C]     [N] [G]         [W]     [P]
+[W]     [C] [Q] [S]     [C]     [M]
+[L]     [W] [B] [Z]     [F] [S] [V]
+[R]     [G] [H] [F] [P] [V] [M] [T]
+[M] [L] [R] [D] [L] [N] [P] [D] [W]
+[F] [Q] [S] [C] [G] [G] [Z] [P] [N]
+[Q] [D] [P] [L] [V] [D] [D] [C] [Z]
+ 1   2   3   4   5   6   7   8   9
+
+move 1 from 9 to 2
+move 4 from 6 to 1
+move 4 from 2 to 6
+move 5 from 8 to 7
+move 4 from 9 to 2
+move 1 from 5 to 8
+move 1 from 3 to 1
+move 2 from 3 to 1
+move 1 from 4 to 2
+move 11 from 7 to 2
+move 5 from 5 to 1
+move 1 from 6 to 8
+move 1 from 7 to 6
+move 3 from 6 to 7
+move 1 from 3 to 2
+move 1 from 6 to 8
+move 11 from 2 to 1
+move 1 from 9 to 8
+move 1 from 3 to 7
+move 4 from 7 to 9
+move 3 from 3 to 7
+move 4 from 8 to 2
+move 3 from 7 to 6
+move 2 from 6 to 3
+move 5 from 4 to 1
+move 1 from 6 to 5
+move 26 from 1 to 7
+move 1 from 4 to 6
+move 22 from 7 to 5
+move 4 from 9 to 1
+move 3 from 7 to 3
+move 1 from 6 to 3
+move 6 from 1 to 7
+move 2 from 7 to 5
+move 8 from 1 to 9
+move 4 from 3 to 4
+move 10 from 2 to 7
+move 6 from 7 to 4
+move 2 from 9 to 5
+move 1 from 5 to 1
+move 8 from 4 to 1
+move 2 from 5 to 9
+move 1 from 3 to 6
+move 1 from 9 to 1
+move 1 from 3 to 6
+move 2 from 5 to 2
+move 1 from 4 to 2
+move 1 from 2 to 3
+move 7 from 1 to 4
+move 9 from 7 to 4
+move 1 from 3 to 4
+move 2 from 2 to 4
+move 5 from 9 to 6
+move 1 from 4 to 5
+move 2 from 9 to 3
+move 1 from 1 to 6
+move 2 from 6 to 1
+move 2 from 6 to 5
+move 2 from 9 to 7
+move 1 from 3 to 9
+move 1 from 9 to 5
+move 2 from 7 to 3
+move 1 from 1 to 7
+move 7 from 4 to 5
+move 2 from 1 to 2
+move 3 from 3 to 8
+move 3 from 8 to 9
+move 31 from 5 to 8
+move 1 from 7 to 1
+move 1 from 2 to 1
+move 1 from 1 to 5
+move 1 from 5 to 6
+move 2 from 5 to 7
+move 10 from 4 to 9
+move 5 from 6 to 2
+move 3 from 2 to 6
+move 2 from 7 to 8
+move 1 from 6 to 3
+move 1 from 4 to 1
+move 1 from 3 to 6
+move 1 from 4 to 2
+move 2 from 1 to 2
+move 1 from 8 to 7
+move 10 from 8 to 2
+move 13 from 2 to 9
+move 1 from 1 to 5
+move 18 from 8 to 2
+move 21 from 9 to 6
+move 1 from 7 to 8
+move 2 from 9 to 7
+move 1 from 2 to 3
+move 1 from 7 to 8
+move 9 from 2 to 4
+move 1 from 7 to 8
+move 3 from 9 to 1
+move 1 from 8 to 1
+move 6 from 2 to 3
+move 5 from 4 to 7
+move 1 from 5 to 8
+move 2 from 4 to 3
+move 5 from 7 to 3
+move 2 from 2 to 7
+move 15 from 6 to 1
+move 12 from 1 to 2
+move 6 from 2 to 9
+move 4 from 9 to 5
+move 4 from 5 to 6
+move 14 from 3 to 9
+move 1 from 6 to 7
+move 1 from 7 to 2
+move 1 from 7 to 8
+move 9 from 2 to 6
+move 1 from 1 to 6
+move 2 from 9 to 8
+move 4 from 9 to 7
+move 1 from 1 to 5
+move 8 from 8 to 3
+move 1 from 5 to 4
+move 2 from 1 to 2
+move 3 from 1 to 4
+move 9 from 6 to 2
+move 1 from 7 to 4
+move 1 from 8 to 2
+move 1 from 6 to 4
+move 4 from 7 to 8
+move 12 from 6 to 8
+move 3 from 2 to 1
+move 6 from 8 to 7
+move 5 from 3 to 6
+move 3 from 3 to 6
+move 3 from 1 to 3
+move 8 from 2 to 9
+move 2 from 4 to 5
+move 2 from 7 to 2
+move 10 from 8 to 5
+move 3 from 3 to 2
+move 10 from 5 to 3
+move 1 from 4 to 3
+move 1 from 2 to 1
+move 1 from 1 to 7
+move 14 from 9 to 6
+move 5 from 2 to 4
+move 15 from 6 to 5
+move 3 from 9 to 3
+move 1 from 8 to 6
+move 1 from 3 to 8
+move 7 from 3 to 8
+move 16 from 5 to 1
+move 2 from 7 to 1
+move 1 from 5 to 9
+move 2 from 9 to 3
+move 15 from 1 to 5
+move 3 from 8 to 2
+move 3 from 3 to 1
+move 3 from 7 to 3
+move 8 from 4 to 6
+move 5 from 1 to 6
+move 9 from 5 to 7
+move 2 from 8 to 3
+move 2 from 2 to 7
+move 1 from 1 to 4
+move 2 from 5 to 8
+move 4 from 3 to 1
+move 4 from 8 to 1
+move 1 from 8 to 6
+move 9 from 7 to 6
+move 2 from 7 to 5
+move 3 from 1 to 8
+move 1 from 4 to 8
+move 1 from 2 to 4
+move 12 from 6 to 2
+move 3 from 8 to 6
+move 1 from 4 to 7
+move 2 from 6 to 8
+move 5 from 5 to 9
+move 13 from 2 to 9
+move 2 from 4 to 7
+move 13 from 9 to 5
+move 2 from 6 to 5
+move 1 from 3 to 9
+move 6 from 9 to 4
+move 5 from 1 to 3
+move 1 from 7 to 9
+move 15 from 5 to 8
+move 2 from 4 to 7
+move 2 from 4 to 6
+move 1 from 4 to 6
+move 1 from 5 to 7
+move 18 from 6 to 2
+move 2 from 7 to 3
+move 3 from 6 to 7
+move 3 from 2 to 8
+move 5 from 7 to 3
+move 1 from 9 to 6
+move 2 from 3 to 8
+move 11 from 3 to 2
+move 2 from 2 to 9
+move 1 from 6 to 2
+move 1 from 7 to 5
+move 1 from 5 to 9
+move 9 from 8 to 4
+move 1 from 4 to 6
+move 2 from 3 to 1
+move 2 from 1 to 5
+move 12 from 8 to 3
+move 1 from 8 to 2
+move 14 from 3 to 4
+move 1 from 6 to 4
+move 1 from 5 to 4
+move 20 from 2 to 7
+move 2 from 9 to 5
+move 1 from 5 to 3
+move 1 from 9 to 2
+move 1 from 2 to 8
+move 2 from 2 to 3
+move 5 from 4 to 5
+move 6 from 5 to 7
+move 2 from 8 to 2
+move 3 from 3 to 9
+move 5 from 4 to 5
+move 2 from 9 to 7
+move 2 from 2 to 3
+move 1 from 9 to 3
+move 22 from 7 to 3
+move 4 from 7 to 4
+move 24 from 3 to 6
+move 4 from 2 to 6
+move 18 from 6 to 9
+move 15 from 4 to 6
+move 8 from 6 to 3
+move 6 from 6 to 1
+move 7 from 9 to 6
+move 2 from 7 to 4
+move 8 from 3 to 9
+move 14 from 6 to 3
+move 2 from 3 to 9
+move 1 from 9 to 6
+move 13 from 9 to 1
+move 3 from 4 to 5
+move 1 from 9 to 6
+move 5 from 1 to 8
+move 3 from 3 to 9
+move 2 from 1 to 5
+move 8 from 5 to 8
+move 10 from 3 to 5
+move 3 from 4 to 6
+move 6 from 1 to 9
+move 4 from 5 to 3
+move 5 from 8 to 2
+move 6 from 6 to 3
+move 7 from 3 to 6
+move 1 from 3 to 4
+move 5 from 8 to 7
+move 5 from 2 to 6
+move 2 from 7 to 3
+move 3 from 7 to 3
+move 1 from 4 to 9
+move 9 from 6 to 9
+move 2 from 6 to 2
+move 1 from 8 to 2
+move 2 from 8 to 7
+move 5 from 1 to 5
+move 1 from 1 to 4
+move 13 from 5 to 7
+move 5 from 3 to 7
+move 1 from 5 to 6
+move 1 from 4 to 6
+move 3 from 2 to 8
+move 1 from 3 to 5
+move 1 from 3 to 8
+move 14 from 7 to 4
+move 1 from 5 to 6
+move 7 from 6 to 9
+move 6 from 7 to 9
+move 2 from 8 to 9
+move 2 from 8 to 1
+move 31 from 9 to 1
+move 13 from 4 to 2
+move 1 from 4 to 3
+move 10 from 2 to 7
+move 1 from 3 to 4
+move 1 from 2 to 7
+move 3 from 7 to 8
+move 1 from 4 to 1
+move 3 from 8 to 5
+move 32 from 1 to 5
+move 3 from 9 to 7
+move 4 from 9 to 6
+move 2 from 2 to 7
+move 2 from 1 to 7
+move 1 from 6 to 1
+move 1 from 9 to 4
+move 3 from 6 to 4
+move 1 from 1 to 8
+move 15 from 5 to 1
+move 1 from 8 to 4
+move 9 from 5 to 7
+move 1 from 9 to 8
+move 1 from 8 to 1
+move 10 from 1 to 9
+move 1 from 4 to 2
+move 2 from 9 to 5
+move 4 from 9 to 6
+move 1 from 2 to 7
+move 3 from 4 to 2
+move 1 from 1 to 5
+move 5 from 1 to 5
+move 1 from 4 to 9
+move 3 from 6 to 7
+move 23 from 7 to 6
+move 1 from 2 to 4
+move 1 from 2 to 5
+move 9 from 5 to 4
+move 1 from 2 to 5
+move 9 from 5 to 6
+move 1 from 9 to 7
+move 1 from 9 to 3
+move 3 from 9 to 4
+move 14 from 6 to 3
+move 5 from 7 to 4
+move 1 from 7 to 5
+move 1 from 5 to 9
+move 2 from 5 to 6
+move 16 from 6 to 2
+move 2 from 6 to 1
+move 7 from 4 to 8
+move 2 from 1 to 2
+move 4 from 3 to 5
+move 5 from 4 to 7
+move 2 from 6 to 7
+move 4 from 4 to 1
+move 4 from 8 to 9
+move 1 from 4 to 5
+move 1 from 6 to 8
+move 1 from 4 to 9
+move 4 from 1 to 7
+move 1 from 9 to 4
+move 2 from 2 to 7
+move 7 from 3 to 9
+move 15 from 2 to 3
+move 4 from 8 to 6
+move 1 from 4 to 7
+move 2 from 9 to 7
+move 1 from 6 to 8
+move 2 from 7 to 2
+move 5 from 7 to 2
+move 1 from 5 to 2
+move 6 from 2 to 9
+move 3 from 7 to 1
+move 3 from 1 to 2
+move 3 from 7 to 1
+move 2 from 2 to 9
+move 2 from 6 to 9
+move 1 from 8 to 3
+move 19 from 3 to 9
+move 1 from 6 to 3
+move 3 from 7 to 4
+move 1 from 2 to 5
+move 2 from 1 to 9
+move 2 from 2 to 3
+move 33 from 9 to 7
+move 1 from 1 to 7
+move 3 from 3 to 7
+move 1 from 3 to 2
+move 1 from 5 to 8
+move 4 from 9 to 7
+move 1 from 5 to 2
+move 2 from 4 to 9
+move 4 from 9 to 7
+move 3 from 2 to 1
+move 1 from 4 to 3
+move 1 from 9 to 7
+move 1 from 8 to 3
+move 7 from 7 to 3
+move 3 from 1 to 9
+move 4 from 9 to 7
+move 4 from 5 to 8
+move 3 from 3 to 4
+move 3 from 4 to 5
+move 3 from 3 to 6
+move 2 from 6 to 5
+move 38 from 7 to 5
+move 40 from 5 to 3
+move 4 from 8 to 9
+move 1 from 6 to 9
+move 1 from 5 to 1
+move 3 from 7 to 6
+move 1 from 7 to 5
+move 38 from 3 to 8
+move 1 from 1 to 9
+move 3 from 9 to 6
+move 5 from 3 to 9
+move 4 from 8 to 6
+move 1 from 7 to 1
+move 3 from 5 to 9
+move 1 from 1 to 2
+move 10 from 8 to 3
+move 5 from 8 to 1
+move 3 from 1 to 2
+move 9 from 6 to 7
+move 9 from 3 to 5
+move 1 from 7 to 6
+move 1 from 3 to 8
+move 1 from 7 to 9
+move 1 from 1 to 5
+move 1 from 1 to 3
+move 1 from 9 to 2
+move 4 from 2 to 3
+move 1 from 2 to 4
+move 9 from 8 to 1
+move 2 from 9 to 5
+move 2 from 1 to 2
+move 2 from 3 to 4
+move 6 from 8 to 6
+move 10 from 5 to 3
+move 7 from 3 to 2
+move 2 from 1 to 2
+move 5 from 1 to 7
+move 7 from 9 to 6
+move 7 from 6 to 5
+move 1 from 4 to 3
+move 7 from 7 to 4
+move 5 from 3 to 9
+move 7 from 2 to 6
+move 4 from 7 to 8
+move 5 from 8 to 9
+move 1 from 2 to 6
+move 1 from 3 to 5
+move 2 from 2 to 8
+move 8 from 4 to 6
+move 7 from 9 to 7
+move 4 from 7 to 9
+move 7 from 9 to 3
+move 8 from 3 to 1
+move 6 from 5 to 9
+move 8 from 1 to 8
+move 13 from 8 to 4
+move 3 from 9 to 6
+move 1 from 8 to 6
+move 1 from 7 to 3
+move 2 from 4 to 1
+move 5 from 9 to 1
+move 1 from 3 to 7
+move 15 from 6 to 1
+move 1 from 7 to 9
+move 10 from 4 to 7
+move 11 from 7 to 5
+move 17 from 1 to 6
+move 1 from 9 to 3
+move 6 from 6 to 1
+move 3 from 5 to 3
+move 2 from 4 to 5
+move 2 from 7 to 8
+move 12 from 5 to 3
+move 13 from 6 to 9
+move 2 from 8 to 2
+move 2 from 5 to 1
+move 16 from 3 to 8
+move 3 from 2 to 3
+move 2 from 3 to 7
+move 2 from 7 to 9
+move 1 from 3 to 7
+move 4 from 8 to 4
+move 2 from 4 to 8
+move 5 from 1 to 5
+move 2 from 4 to 7
+move 6 from 6 to 8
+move 2 from 8 to 5
+move 2 from 1 to 4
+move 5 from 8 to 7
+move 5 from 6 to 3
+move 6 from 9 to 8
+move 2 from 9 to 2
+move 1 from 1 to 7
+move 4 from 5 to 3
+move 2 from 2 to 3
+move 1 from 4 to 9
+move 10 from 3 to 6
+move 1 from 3 to 7
+move 10 from 7 to 2
+move 2 from 5 to 3
+move 1 from 4 to 2
+move 2 from 6 to 8
+move 3 from 6 to 5
+move 1 from 6 to 1
+move 7 from 2 to 3
+move 6 from 8 to 7
+move 4 from 6 to 3
+move 14 from 8 to 6
+move 11 from 6 to 8
+move 1 from 1 to 4
+move 6 from 7 to 2
+move 3 from 5 to 8
+move 4 from 1 to 7
+move 1 from 2 to 8
+move 1 from 2 to 6
+move 1 from 3 to 4
+move 1 from 5 to 6
+move 7 from 8 to 6
+move 9 from 3 to 2
+move 1 from 8 to 5

day5/main.py

@@ -0,0 +1,86 @@
+from dataclasses import dataclass
+
+from common.file import read_data
+
+test_dataset = [
+    "    [D]    ",
+    "[N] [C]    ",
+    "[Z] [M] [P]",
+    " 1   2   3 ",
+    "",
+    "move 1 from 2 to 1",
+    "move 3 from 1 to 3",
+    "move 2 from 2 to 1",
+    "move 1 from 1 to 2",
+]
+
+
+@dataclass(frozen=True)
+class Move:
+    quantity: int
+    of: int
+    to: int
+
+
+def process_data(data: list[str]) -> tuple[list[list[str]], list[Move]]:
+    rows = []
+    steps = []
+    for line in data:
+        if line == "" or line.strip()[0] == "1":
+            continue
+        if line[0] == "m":
+            steps.append(line)
+        else:
+            rows.append(line)
+
+    stacks = _build_stacks(rows)
+    instructions = _build_instructions(steps)
+
+    return stacks, instructions
+
+
+def _build_stacks(rows: list[str]) -> list[list[str]]:
+    stacks = []
+    i = 0
+    while i < len(rows[0]):
+        stack = []
+        for row in rows:
+            crate = row[i + 1 : i + 2]
+            if crate.strip() != "":
+                stack.insert(0, crate)
+
+        i += 4
+        stacks.append(stack)
+    return stacks
+
+
+def _build_instructions(instructions: list[str]) -> list[Move]:
+    moves = []
+    for step in instructions:
+        splits = step.split(" ")
+        qty = int(splits[1])
+        of = int(splits[3]) - 1
+        to = int(splits[5]) - 1
+        moves.append(Move(quantity=qty, of=of, to=to))
+
+    return moves
+
+
+def find_top_crates(stacks: list[list[str]], instructions: list[Move]) -> str:
+    for step in instructions:
+        for _ in range(step.quantity):
+            stacks[step.to].append(stacks[step.of].pop())
+
+    return "".join(stack[-1] for stack in stacks)
+
+
+def top_crates(data: list) -> str:
+    stacks, instructions = process_data(data)
+    return find_top_crates(stacks, instructions)
+
+
+if __name__ == "__main__":
+    dataset = read_data()
+
+    res = top_crates(dataset)
+    assert res == "CMZ", f"{res} is not the right value"