Day02 2019

2019/src/main/java/be/vandewalleh/aoc/Day01.java

@@ -36,13 +36,12 @@ public class Day01 {
         var total = 0;
         for (var mass : input) {
             int fuel = fuel(mass);
-            int subTotal = fuel;
+            total += fuel;
             while (true) {
                 fuel = fuel(fuel);
                 if (fuel <= 0) break;
-                subTotal += fuel;
+                total += fuel;
             }
-            total += subTotal;
         }
         return total;
     }

2019/src/main/java/be/vandewalleh/aoc/Day02.java

@@ -0,0 +1,44 @@
+package be.vandewalleh.aoc;
+
+import be.vandewalleh.aoc.intcode.IntCodeInterpreter;
+import be.vandewalleh.aoc.utils.factory.Days;
+import be.vandewalleh.aoc.utils.input.Csv;
+import be.vandewalleh.aoc.utils.input.Day;
+import be.vandewalleh.aoc.utils.input.Input;
+
+@Day(2)
+public class Day02 {
+
+    public static void main(String[] args) {
+        var day = Days.createDay(Day02.class);
+        System.out.println(day.part1());
+        System.out.println(day.part2());
+    }
+
+    private final int[] input;
+
+    public Day02(@Csv Input<int[]> input) {
+        this.input = input.getValue();
+    }
+
+    private long runInterpreterWith(int noun, int verb) {
+        var interpreter = new IntCodeInterpreter(input);
+        interpreter.setNoun(noun);
+        interpreter.setVerb(verb);
+        interpreter.run();
+        return interpreter.getOutput();
+    }
+
+    public long part1() {
+        return runInterpreterWith(12, 2);
+    }
+
+    public int part2() {
+        for (var noun = 0; noun < 99; noun++) {
+            for (var verb = 0; verb < 99; verb++) {
+                if (runInterpreterWith(noun, verb) == 19690720L) return 100 * noun + verb;
+            }
+        }
+        return -1;
+    }
+}

2019/src/main/java/be/vandewalleh/aoc/intcode/IntCodeInterpreter.java

@@ -0,0 +1,48 @@
+package be.vandewalleh.aoc.intcode;
+
+import java.util.Arrays;
+
+public class IntCodeInterpreter {
+    private final long[] memory;
+
+    public IntCodeInterpreter(long[] memory) {
+        var copy = new long[memory.length];
+        System.arraycopy(memory, 0, copy, 0, memory.length);
+        this.memory = copy;
+    }
+
+    public IntCodeInterpreter(int[] memory) {
+        this.memory = Arrays.stream(memory).asLongStream().toArray();
+    }
+
+    public void setNoun(long noun) {
+        memory[1] = noun;
+    }
+
+    public void setVerb(long verb) {
+        memory[2] = verb;
+    }
+
+    public long getOutput() {
+        return memory[0];
+    }
+
+    public void run() {
+        var pointer = 0;
+
+        loop:
+        while (true) {
+            var optionalOpCode = OpCode.from((int) memory[pointer]);
+            var opCode = optionalOpCode.orElseThrow(() -> new IllegalArgumentException("Invalid OpCode"));
+            var args = Arrays.copyOfRange(memory, pointer + 1, pointer + opCode.params + 1);
+            switch (opCode) {
+                case Add -> memory[(int) args[2]] = memory[(int) args[0]] + memory[(int) args[1]];
+                case Multiply -> memory[(int) args[2]] = memory[(int) args[0]] * memory[(int) args[1]];
+                case Halt -> {
+                    break loop;
+                }
+            }
+            pointer += opCode.params + 1;
+        }
+    }
+}

2019/src/main/java/be/vandewalleh/aoc/intcode/OpCode.java

@@ -0,0 +1,24 @@
+package be.vandewalleh.aoc.intcode;
+
+import java.util.Optional;
+
+public enum OpCode {
+    Add(1, 3),
+    Multiply(2, 3),
+    Halt(99, 0);
+
+    public final int value;
+    public final int params;
+
+    OpCode(int value, int params) {
+        this.value = value;
+        this.params = params;
+    }
+
+    public static Optional<OpCode> from(int value) {
+        for (OpCode opCode : OpCode.values()) {
+            if (opCode.value == value) return Optional.of(opCode);
+        }
+        return Optional.empty();
+    }
+}

2019/src/main/resources/day02.txt

@@ -0,0 +1 @@
+1,0,0,3,1,1,2,3,1,3,4,3,1,5,0,3,2,6,1,19,1,5,19,23,2,6,23,27,1,27,5,31,2,9,31,35,1,5,35,39,2,6,39,43,2,6,43,47,1,5,47,51,2,9,51,55,1,5,55,59,1,10,59,63,1,63,6,67,1,9,67,71,1,71,6,75,1,75,13,79,2,79,13,83,2,9,83,87,1,87,5,91,1,9,91,95,2,10,95,99,1,5,99,103,1,103,9,107,1,13,107,111,2,111,10,115,1,115,5,119,2,13,119,123,1,9,123,127,1,5,127,131,2,131,6,135,1,135,5,139,1,139,6,143,1,143,6,147,1,2,147,151,1,151,5,0,99,2,14,0,0