Day 5, puzzle 1

src/main/kotlin/com/basdado/adventofcode/day5/Day5.kt

@@ -0,0 +1,107 @@
+package com.basdado.adventofcode.day5
+
+import com.basdado.adventofcode.day5.Day5.puzzle1
+import com.basdado.adventofcode.line
+
+const val DAY5_INPUT_PATH = "/day/5/input.txt"
+
+
+fun main() {
+    puzzle1()
+}
+
+object Day5 {
+
+    val opcodes = mapOf(
+        Pair(1, OpCode(1, 3, ::add)),
+        Pair(2, OpCode(2, 3, ::multiply)),
+        Pair(3, OpCode(3, 1, ::saveInput)),
+        Pair(4, OpCode(4, 1, ::writeOutput))
+    )
+
+    fun puzzle1() {
+
+        val program = Program(line(DAY5_INPUT_PATH).split(",").map { it.toInt() }.toIntArray(),
+            1)
+
+        var pointer = 0
+        while (program.data[pointer] != 99) {
+
+            println(pointer)
+
+            val instruction = Instruction.parse(program.data[pointer], pointer)
+            instruction.opcode.operation.invoke(instruction, program)
+
+            pointer += instruction.opcode.paramCount + 1
+        }
+    }
+
+    class Instruction(
+        val paramModeImmediate: BooleanArray,
+        val opcode: OpCode,
+        val pos: Int
+        ) {
+
+        companion object {
+            fun parse(input: Int, pointer: Int): Instruction {
+                val opcode = opcodes[input % 100] ?: throw IllegalArgumentException("Uknown opcode for operation $input")
+                val paramModes = BooleanArray(opcode.paramCount)
+                for (i in 0 until opcode.paramCount) {
+                    paramModes[i] = (input % pow10(i + 3)) / pow10(i + 2) == 1
+                }
+                return Instruction(paramModes, opcode, pointer)
+            }
+        }
+    }
+
+    class Program(val data: IntArray, val input: Int) {
+
+        fun getValue(instruction: Instruction, i: Int): Int {
+            return if (instruction.paramModeImmediate[i]) {
+                data[instruction.pos + i + 1]
+            } else {
+                data[data[instruction.pos + i + 1]]
+            }
+        }
+
+        fun setValue(instruction: Instruction, i: Int, x: Int) {
+            // Setters don't care about parameter modes, they are always "position" based
+            data[data[instruction.pos + i + 1]] = x
+        }
+    }
+
+    fun pow10(n: Int): Int {
+        return when (n) {
+            0 -> 1
+            1 -> 10
+            2 -> 100
+            3 -> 1000
+            4 -> 10000
+            5 -> 100000
+            6 -> 1000000
+            7 -> 10000000
+            8 -> 100000000
+            9 -> 1000000000
+            else -> throw IllegalArgumentException("Int overflowing with pow10($n)")
+        }
+    }
+    private fun add(instruction: Instruction, program: Program) {
+        program.setValue(instruction, 2, program.getValue(instruction, 0) + program.getValue(instruction, 1))
+    }
+
+    private fun multiply(instruction: Instruction, program: Program) {
+        program.setValue(instruction, 2, program.getValue(instruction, 0) * program.getValue(instruction, 1))
+    }
+
+    private fun saveInput(instruction: Instruction, program: Program) {
+        program.setValue(instruction, 0, program.input)
+    }
+
+    private fun writeOutput(instruction: Instruction, program: Program) {
+        // I guess we just write to console?
+        println(program.getValue(instruction, 0))
+    }
+
+    data class OpCode(val code: Int, val paramCount: Int, val operation: (instruction: Instruction, program: Program) -> Unit)
+
+}

src/main/resources/day/5/input.txt

@@ -0,0 +1 @@
+3,225,1,225,6,6,1100,1,238,225,104,0,1002,36,25,224,1001,224,-2100,224,4,224,1002,223,8,223,101,1,224,224,1,223,224,223,1102,31,84,225,1102,29,77,225,1,176,188,224,101,-42,224,224,4,224,102,8,223,223,101,3,224,224,1,223,224,223,2,196,183,224,1001,224,-990,224,4,224,1002,223,8,223,101,7,224,224,1,224,223,223,102,14,40,224,101,-1078,224,224,4,224,1002,223,8,223,1001,224,2,224,1,224,223,223,1001,180,64,224,101,-128,224,224,4,224,102,8,223,223,101,3,224,224,1,223,224,223,1102,24,17,224,1001,224,-408,224,4,224,1002,223,8,223,101,2,224,224,1,223,224,223,1101,9,66,224,1001,224,-75,224,4,224,1002,223,8,223,1001,224,6,224,1,223,224,223,1102,18,33,225,1101,57,64,225,1102,45,11,225,1101,45,9,225,1101,11,34,225,1102,59,22,225,101,89,191,224,1001,224,-100,224,4,224,1002,223,8,223,1001,224,1,224,1,223,224,223,4,223,99,0,0,0,677,0,0,0,0,0,0,0,0,0,0,0,1105,0,99999,1105,227,247,1105,1,99999,1005,227,99999,1005,0,256,1105,1,99999,1106,227,99999,1106,0,265,1105,1,99999,1006,0,99999,1006,227,274,1105,1,99999,1105,1,280,1105,1,99999,1,225,225,225,1101,294,0,0,105,1,0,1105,1,99999,1106,0,300,1105,1,99999,1,225,225,225,1101,314,0,0,106,0,0,1105,1,99999,8,226,677,224,1002,223,2,223,1006,224,329,1001,223,1,223,108,226,226,224,1002,223,2,223,1006,224,344,1001,223,1,223,7,677,226,224,102,2,223,223,1005,224,359,101,1,223,223,7,226,677,224,102,2,223,223,1006,224,374,101,1,223,223,1008,677,226,224,1002,223,2,223,1006,224,389,101,1,223,223,8,677,677,224,1002,223,2,223,1005,224,404,101,1,223,223,8,677,226,224,102,2,223,223,1005,224,419,1001,223,1,223,1107,677,226,224,102,2,223,223,1005,224,434,1001,223,1,223,1107,226,677,224,1002,223,2,223,1006,224,449,1001,223,1,223,107,677,226,224,1002,223,2,223,1005,224,464,1001,223,1,223,1008,677,677,224,1002,223,2,223,1006,224,479,1001,223,1,223,1108,677,226,224,1002,223,2,223,1006,224,494,1001,223,1,223,1108,677,677,224,1002,223,2,223,1006,224,509,1001,223,1,223,107,677,677,224,1002,223,2,223,1005,224,524,101,1,223,223,1007,677,226,224,102,2,223,223,1005,224,539,1001,223,1,223,1107,226,226,224,1002,223,2,223,1006,224,554,1001,223,1,223,1008,226,226,224,1002,223,2,223,1006,224,569,101,1,223,223,1108,226,677,224,1002,223,2,223,1006,224,584,101,1,223,223,108,677,677,224,1002,223,2,223,1006,224,599,1001,223,1,223,1007,677,677,224,102,2,223,223,1006,224,614,101,1,223,223,107,226,226,224,102,2,223,223,1006,224,629,101,1,223,223,1007,226,226,224,102,2,223,223,1005,224,644,1001,223,1,223,108,226,677,224,102,2,223,223,1005,224,659,1001,223,1,223,7,677,677,224,102,2,223,223,1006,224,674,1001,223,1,223,4,223,99,226