day 5 was so cool

Author: analogrelay

2019/inputs/day05/input.txt

@@ -0,0 +1 @@
+3,225,1,225,6,6,1100,1,238,225,104,0,1102,9,19,225,1,136,139,224,101,-17,224,224,4,224,102,8,223,223,101,6,224,224,1,223,224,223,2,218,213,224,1001,224,-4560,224,4,224,102,8,223,223,1001,224,4,224,1,223,224,223,1102,25,63,224,101,-1575,224,224,4,224,102,8,223,223,1001,224,4,224,1,223,224,223,1102,55,31,225,1101,38,15,225,1001,13,88,224,1001,224,-97,224,4,224,102,8,223,223,101,5,224,224,1,224,223,223,1002,87,88,224,101,-3344,224,224,4,224,102,8,223,223,1001,224,7,224,1,224,223,223,1102,39,10,225,1102,7,70,225,1101,19,47,224,101,-66,224,224,4,224,1002,223,8,223,1001,224,6,224,1,224,223,223,1102,49,72,225,102,77,166,224,101,-5544,224,224,4,224,102,8,223,223,1001,224,4,224,1,223,224,223,101,32,83,224,101,-87,224,224,4,224,102,8,223,223,1001,224,3,224,1,224,223,223,1101,80,5,225,1101,47,57,225,4,223,99,0,0,0,677,0,0,0,0,0,0,0,0,0,0,0,1105,0,99999,1105,227,247,1105,1,99999,1005,227,99999,1005,0,256,1105,1,99999,1106,227,99999,1106,0,265,1105,1,99999,1006,0,99999,1006,227,274,1105,1,99999,1105,1,280,1105,1,99999,1,225,225,225,1101,294,0,0,105,1,0,1105,1,99999,1106,0,300,1105,1,99999,1,225,225,225,1101,314,0,0,106,0,0,1105,1,99999,1008,677,226,224,1002,223,2,223,1005,224,329,1001,223,1,223,107,226,677,224,1002,223,2,223,1006,224,344,101,1,223,223,1007,677,677,224,1002,223,2,223,1006,224,359,1001,223,1,223,8,677,226,224,102,2,223,223,1005,224,374,101,1,223,223,108,226,677,224,102,2,223,223,1006,224,389,1001,223,1,223,1008,677,677,224,1002,223,2,223,1006,224,404,1001,223,1,223,1107,677,677,224,102,2,223,223,1005,224,419,1001,223,1,223,1008,226,226,224,102,2,223,223,1005,224,434,101,1,223,223,8,226,677,224,1002,223,2,223,1006,224,449,101,1,223,223,1007,677,226,224,102,2,223,223,1005,224,464,1001,223,1,223,107,677,677,224,1002,223,2,223,1005,224,479,1001,223,1,223,1107,226,677,224,1002,223,2,223,1005,224,494,1001,223,1,223,7,677,677,224,102,2,223,223,1006,224,509,101,1,223,223,1007,226,226,224,1002,223,2,223,1005,224,524,101,1,223,223,7,677,226,224,102,2,223,223,1005,224,539,101,1,223,223,8,226,226,224,1002,223,2,223,1006,224,554,101,1,223,223,7,226,677,224,102,2,223,223,1005,224,569,101,1,223,223,1108,677,226,224,1002,223,2,223,1005,224,584,101,1,223,223,108,677,677,224,1002,223,2,223,1006,224,599,101,1,223,223,107,226,226,224,1002,223,2,223,1006,224,614,101,1,223,223,1108,226,226,224,1002,223,2,223,1005,224,629,1001,223,1,223,1107,677,226,224,1002,223,2,223,1005,224,644,101,1,223,223,108,226,226,224,1002,223,2,223,1005,224,659,101,1,223,223,1108,226,677,224,1002,223,2,223,1005,224,674,1001,223,1,223,4,223,99,226

2019/src/main/kotlin/adventofcode/common/IntcodeComputer.kt

@@ -1,32 +1,136 @@
 package adventofcode.common
 
+import java.io.File
+
+enum class ParameterMode {
+    Position,
+    Immediate;
+
+    companion object {
+        public fun decode(modeVal: Int) = ParameterMode.values()[modeVal]
+    }
+}
+
+data class Instruction(public val opcode: Int, public val modes: List<ParameterMode>) {
+    companion object {
+        fun decode(encoded: Int): Instruction {
+            // Get the opcode, which is the lower two digits
+            val opcode = encoded % 100
+            var modeFlags = encoded / 100
+
+            val modes = generateSequence {
+                if (modeFlags == 0) {
+                    null
+                } else {
+                    val mode = ParameterMode.decode(modeFlags % 10)
+                    modeFlags = modeFlags / 10
+                    mode
+                }
+            }.toList()
+
+            return Instruction(opcode, modes)
+        }
+    }
+
+    public fun modeFor(parameterIndex: Int) =
+        if (parameterIndex >= modes.size) {
+            ParameterMode.Position
+        } else {
+            modes[parameterIndex]
+        }
+}
+
 public class IntcodeComputer(public var memory: IntArray, private val trace: Boolean = false) {
     public var programCounter = 0
 
+    companion object {
+        public fun fromProgram(input: String, trace: Boolean = false): IntcodeComputer {
+            val memory = input.split(",").map { it.toInt() }.toIntArray()
+            return IntcodeComputer(memory, trace)
+        }
+
+        public fun fromProgramFile(inputFile: String, trace: Boolean = false): IntcodeComputer =
+            fromProgram(File(inputFile).readText().trim(), trace)
+    }
+
+    private fun readNext(): Int {
+        val value = memory[programCounter]
+        programCounter += 1
+        return value
+    }
+
+    private fun readNextByMode(mode: ParameterMode): Int {
+        val value = readNext()
+
+        return when (mode) {
+            ParameterMode.Position -> memory[value]
+            ParameterMode.Immediate -> value
+        }
+    }
+
     // Run a single step of the program
     public fun step(): Boolean {
-       val opcode = memory[programCounter]
+        var startPc = programCounter
+        val instruction = Instruction.decode(readNext())
 
-       if (opcode == 99) {
-           return false
-       }
+        fun execBinop(op: (Int, Int) -> Int) {
+            val x = readNextByMode(instruction.modeFor(0))
+            val y = readNextByMode(instruction.modeFor(1))
+            memory[readNext()] = op(x, y)
+        }
+
+        fun jumpIf(cond: (Int) -> Boolean) {
+           val x = readNextByMode(instruction.modeFor(0))
+
+           // Must read the target even if we don't set it.
+           val loc = readNextByMode(instruction.modeFor(1))
+           if (cond(x)) {
+               programCounter = loc
+           }
+        }
 
-       val input1Addr = memory[programCounter + 1] 
-       val input2Addr = memory[programCounter + 2] 
-       val outputAddr = memory[programCounter + 3] 
+        when (instruction.opcode) {
+            // Add
+            1 -> execBinop { x, y -> x + y }
 
-       // Load inputs
-       val input1 = memory[input1Addr]
-       val input2 = memory[input2Addr]
+            // Mult
+            2 -> execBinop { x, y -> x * y }
 
-       // Perform operation and store output
-       memory[outputAddr] = execute(opcode, input1, input2)
+            // Output
+            3 -> {
+                print("[Intcode] INPUT: ")
+                val input = readLine()!!.trim().toInt()
+                memory[readNext()] = input
+            }
+            
+            // Input
+            4 -> {
+                val x = readNextByMode(instruction.modeFor(0))
+                println("[Intcode] OUTPUT: $x")
+            }
+            
+            // Jump if true
+            5 -> jumpIf { it != 0 }
+            
+            // Jump if false
+            6 -> jumpIf { it == 0 }
+
+            // Test less than
+            7 -> execBinop { x, y -> if (x < y) { 1 } else { 0 } }
+
+            // Test equals
+            8 -> execBinop { x, y -> if (x == y) { 1 } else { 0 } }
+
+            99 -> {
+                return false
+            }
+            else -> throw Exception("Unknown opcode: ${instruction.opcode}")
+       }
 
        if (trace) {
-           dumpState()
+           dumpState(instruction, startPc, programCounter)
        }
 
-       programCounter += 4
        return true
     }
 
@@ -35,17 +139,16 @@ public class IntcodeComputer(public var memory: IntArray, private val trace: Boo
         while (step()) {}
     }
 
-    private fun execute(opcode: Int, input1: Int, input2: Int): Int =
-       if (opcode == 1) {
-           input1 + input2
-       } else if (opcode == 2) {
-           input1 * input2
-       } else {
-           throw Exception("Unexpected opcode: $opcode");
-       }
-
-    private fun dumpState() {
-        val dump = memory.map { it.toString() }.joinToString(",")
-        println("State: $dump")
+    private fun dumpState(instruction: Instruction, startPc: Int, endPc: Int) {
+        val dump = memory.mapIndexed { idx, i -> 
+            if (idx == startPc) {
+                "{$i}"
+            } else if(idx == endPc) {
+                "[$i]"
+            } else {
+                "$i"
+            }
+        }.joinToString(",")
+        println("${instruction.opcode} => $dump")
     }
-}
+}

2019/src/main/kotlin/adventofcode/day05/main.kt

@@ -1,12 +1,8 @@
 package adventofcode.day05
 
+import adventofcode.common.IntcodeComputer
+
 fun main(args: Array<String>) {
-    val inputFile = if (args.size < 1) {
-        System.err.println("Usage: adventofcode day05 <INPUT FILE>")
-        System.exit(1)
-        throw Exception("Whoop")
-    } else {
-        args[0]
-    }
-    println("Using input file $inputFile");
+    println("Use the 'intcode' command instead!")
+    System.exit(1)
 }

2019/src/main/kotlin/adventofcode/main.kt

@@ -2,12 +2,20 @@ package adventofcode
 
 import java.io.File;
 
+import adventofcode.common.IntcodeComputer
+
 fun main(args: Array<String>) {
     if (args.size < 1 || args[0] == "help") {
         println("Usage: adventofcode <dayNumber> <ARGS...>")
         System.exit(1)
     }
 
+    if (args[0] == "intcode") {
+        println("Running Intcode computer")
+        runIntcode(args.drop(1))
+        return
+    }
+
     val dayName = if (args[0].startsWith("day")) {
         args[0].substring(3)
     } else {
@@ -26,4 +34,28 @@ fun main(args: Array<String>) {
         6 -> adventofcode.day06.main(args.drop(1).toTypedArray())
         else -> throw Exception("Day not yet implemented: $dayNumber")
     }
+}
+
+fun runIntcode(a: List<String>) {
+    var args = a
+
+    val trace = args.contains("--trace")
+    if (trace) {
+        args = args.filterNot { it == "--trace" }
+    }
+
+    if (args.size < 1) {
+        System.err.println("Usage: adventofcode intcode <PROGRAM>")
+        System.err.println("Usage: adventofcode intcode @<PROGRAMFILE>")
+        System.exit(1)
+    }
+
+    val program = if (args[0].startsWith("@")) {
+        File(args[0].substring(1)).readText().trim()
+    } else {
+        args[0]
+    }
+
+    val computer = IntcodeComputer.fromProgram(program, trace)
+    computer.runToHalt()
 }