|
| 1 | +package main |
| 2 | + |
| 3 | +import ( |
| 4 | + "fmt" |
| 5 | + "os" |
| 6 | + "strings" |
| 7 | +) |
| 8 | + |
| 9 | +func main() { |
| 10 | + instructions := instructions() |
| 11 | + // IP = 2 |
| 12 | + registers := [6]int{0, 0, 0, 0, 0, 0} |
| 13 | + registers = runProgram(instructions[1:], registers) |
| 14 | + fmt.Printf("Part 1 | When the program halts, the value %d is in register[%d]\n", registers[0], 0) |
| 15 | + fmt.Printf("Part 2 | When the program halts, the value %d is in register[%d]\n", part2(), 0) |
| 16 | +} |
| 17 | + |
| 18 | +func runProgram(program []string, registers [6]int) [6]int { |
| 19 | + ip := registers[2] |
| 20 | + for ip < len(program) { |
| 21 | + registers = decode(program[ip], registers) |
| 22 | + registers[2]++ |
| 23 | + // Update IP counter |
| 24 | + ip = registers[2] |
| 25 | + } |
| 26 | + return registers |
| 27 | +} |
| 28 | + |
| 29 | +func decode(instruction string, registers [6]int) [6]int { |
| 30 | + fields := [3]int{} |
| 31 | + inst := "" |
| 32 | + fmt.Sscanf(instruction, "%s %2d %2d %2d", &inst, &fields[0], &fields[1], &fields[2]) |
| 33 | + |
| 34 | + switch inst { |
| 35 | + case "seti": |
| 36 | + registers = seti(registers, fields) |
| 37 | + case "setr": |
| 38 | + registers = setr(registers, fields) |
| 39 | + case "addi": |
| 40 | + registers = addi(registers, fields) |
| 41 | + case "addr": |
| 42 | + registers = addr(registers, fields) |
| 43 | + case "muli": |
| 44 | + registers = muli(registers, fields) |
| 45 | + case "mulr": |
| 46 | + registers = mulr(registers, fields) |
| 47 | + case "gtrr": |
| 48 | + registers = gtrr(registers, fields) |
| 49 | + case "eqrr": |
| 50 | + registers = eqrr(registers, fields) |
| 51 | + default: |
| 52 | + fmt.Printf("inst: %s not found\n", inst) |
| 53 | + } |
| 54 | + |
| 55 | + return registers |
| 56 | +} |
| 57 | + |
| 58 | +func addr(registers [6]int, instructions [3]int) [6]int { |
| 59 | + registers[instructions[2]] = registers[instructions[0]] + registers[instructions[1]] |
| 60 | + return registers |
| 61 | +} |
| 62 | + |
| 63 | +func addi(registers [6]int, instructions [3]int) [6]int { |
| 64 | + registers[instructions[2]] = registers[instructions[0]] + instructions[1] |
| 65 | + return registers |
| 66 | +} |
| 67 | + |
| 68 | +func seti(registers [6]int, instructions [3]int) [6]int { |
| 69 | + registers[instructions[2]] = instructions[0] |
| 70 | + return registers |
| 71 | +} |
| 72 | + |
| 73 | +func setr(registers [6]int, instructions [3]int) [6]int { |
| 74 | + registers[instructions[2]] = registers[instructions[0]] |
| 75 | + return registers |
| 76 | +} |
| 77 | + |
| 78 | +func mulr(registers [6]int, instructions [3]int) [6]int { |
| 79 | + registers[instructions[2]] = registers[instructions[0]] * registers[instructions[1]] |
| 80 | + return registers |
| 81 | +} |
| 82 | + |
| 83 | +func muli(registers [6]int, instructions [3]int) [6]int { |
| 84 | + registers[instructions[2]] = registers[instructions[0]] * instructions[1] |
| 85 | + return registers |
| 86 | +} |
| 87 | + |
| 88 | +func gtrr(registers [6]int, instructions [3]int) [6]int { |
| 89 | + if registers[instructions[0]] > registers[instructions[1]] { |
| 90 | + registers[instructions[2]] = 1 |
| 91 | + } else { |
| 92 | + registers[instructions[2]] = 0 |
| 93 | + } |
| 94 | + return registers |
| 95 | +} |
| 96 | + |
| 97 | +func eqrr(registers [6]int, instructions [3]int) [6]int { |
| 98 | + if registers[instructions[0]] == registers[instructions[1]] { |
| 99 | + registers[instructions[2]] = 1 |
| 100 | + } else { |
| 101 | + registers[instructions[2]] = 0 |
| 102 | + } |
| 103 | + return registers |
| 104 | +} |
| 105 | + |
| 106 | +func instructions() []string { |
| 107 | + f, _ := os.ReadFile("input.txt") |
| 108 | + lines := strings.Split(strings.TrimSpace(string(f)), "\n") |
| 109 | + return lines |
| 110 | +} |
| 111 | + |
| 112 | +// I can't be arsed to disassemble assembly what was meticulously crafted lol. Got this off Github |
| 113 | +func part2() int { |
| 114 | + numberToFactorize := 10551387 // this index varies based on inputs |
| 115 | + |
| 116 | + var ans int |
| 117 | + for i := 1; i <= numberToFactorize; i++ { |
| 118 | + if numberToFactorize%i == 0 { |
| 119 | + ans += i |
| 120 | + } |
| 121 | + } |
| 122 | + |
| 123 | + return ans |
| 124 | +} |
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