Day02 2019

2020-12-30 19:18:24 +01:00
parent 4a90257257
commit 4fef41464e
5 changed files with 119 additions and 3 deletions
@@ -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;
+        }
+    }
+}
@@ -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();
+    }
+}