Source: Day 20: Race Condition
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Part 1
Given a maze with exactly one path, find how many single walls you can walk through (remove) that shorten the best path by at least 100 units.
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Given a maze with exactly one path, find how many single walls you can walk through (remove) that shorten the best path by at least 100 units.
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Given a comma delimited list of substrings and a list of strings, count how many of the latter strings can be made up of any (repeating) combination of the former.
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You are given a series of points on a
71x71grid. Taking only the first 1024 points, how long is the shortest path from(0, 0)to(70, 70)?
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Implement a virtual machine. The machine will have 3 unbounded signed registers, 8 opcodes (see below), a variable parameter scheme (see below that). You will be given the initial values of the 3 registers and a program. Find the final output.
| Opcode | Instruction | Description | Notes |
|---|---|---|---|
| 0 | adv reg/val | A = A >> OP | |
| 1 | bxl val | B = B ^ OP | |
| 2 | bst reg/val | B = OP & 0b111 | |
| 3 | jnz val | If a =/= 0, jump to LIT | |
| 4 | bxc ignore | B = B ^ C | Still takes param, but ignores it |
| 5 | out reg/val | Output b | Only outputs lowest 3 bits |
| 6 | bdv reg/val | B = A >> OP | Same as adv but writes to b |
| 7 | cdv reg/val | C = A >> OP | Same as adv but writes to c |
For instructions that can take reg/val, 0 to 3 (inclusive) are treated as literal values, 4 is register A, 5 is B, 6, is C, and 7 is an error (should never happen).
For instructions that only take val, it’s always a literal value in the range 0 to 7 (inclusive).
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Given a maze, what is the shortest path between
SandEwhere walking straight costs one and turning costs 1000.
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Given a warehouse containing floors (
.), walls (#), boxes (O), and the player (@) plus a series of instructions^V<>, move the player according to the instructions, pushing boxes (which in turn can push more boxes).Calculate the sum of
y * 100 + xfor each box’s final position.
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Given a series of robots defined with initial
positionandvelocityon a 101x103 toroidal grid, calculate where the robots will be after 100 iterations. Return the product of the number of robots in each quadrant of the final grid, ignoring the middle lines (since they’re odd).
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Given Button A
(ax, ay), Button B(bx, by), and Prize(px, py); how many times must you press Button A (a) and Button B (b) to reach the Prize? Sum3a + bfor each machine that has a solution.
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Given a
Gridof regions, calculate the sum of the productperimeter * areafor each region.
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Given a sequence of values
v_n, replace each value with the first matching rule:
if v = 0 -> 1- If
vhas an even number of digits, split it (sov = 8675becomes[86, 75])- Otherwise,
v -> v * 2024Calculate how many elements are in the sequence after 25 iterations.