java: add solutions for year 2016, day 16

java/src/benchmark/java/com/github/saser/adventofcode/year2016/day16/BUILD.bazel

@@ -0,0 +1,19 @@
+java_library(
+    name = "benchmark_library",
+    srcs = glob(["*.java"]),
+    deps = [
+        "@maven//:org_openjdk_jmh_jmh_core",
+        "//java/src/main/java/com/github/saser/adventofcode/year2016/day16:day16",
+    ],
+    plugins = ["//java/src/benchmark:annotation_processor"],
+    data = ["//inputs:2016/16"],
+)
+
+java_binary(
+    name = "benchmark",
+    main_class = "org.openjdk.jmh.Main",
+    runtime_deps = [
+        "@maven//:org_openjdk_jmh_jmh_core",
+        ":benchmark_library",
+    ],
+)

java/src/benchmark/java/com/github/saser/adventofcode/year2016/day16/Day16Benchmark.java

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+package com.github.saser.adventofcode.year2016.day16;
+
+import java.io.IOException;
+import java.io.Reader;
+import java.io.StringReader;
+import java.nio.file.Files;
+import java.nio.file.FileSystems;
+import java.util.concurrent.TimeUnit;
+
+import org.openjdk.jmh.annotations.Benchmark;
+import org.openjdk.jmh.annotations.BenchmarkMode;
+import org.openjdk.jmh.annotations.Fork;
+import org.openjdk.jmh.annotations.Measurement;
+import org.openjdk.jmh.annotations.Mode;
+import org.openjdk.jmh.annotations.OutputTimeUnit;
+import org.openjdk.jmh.annotations.Scope;
+import org.openjdk.jmh.annotations.Setup;
+import org.openjdk.jmh.annotations.State;
+import org.openjdk.jmh.annotations.TearDown;
+import org.openjdk.jmh.annotations.Warmup;
+
+@BenchmarkMode(Mode.AverageTime)
+@Fork(1)
+@Measurement(iterations = 1, time = 1)
+@OutputTimeUnit(TimeUnit.MILLISECONDS)
+@State(Scope.Benchmark)
+@Warmup(iterations = 5, time = 1)
+public class Day16Benchmark {
+    private Reader input;
+
+    @Setup
+    public void setup() throws IOException {
+        var path = FileSystems.getDefault().getPath("inputs", "2016", "16");
+        var contents = Files.readString(path);
+        this.input = new StringReader(contents);
+    }
+
+    @Benchmark
+    public void part1() throws IOException {
+        Day16.part1(this.input);
+        this.input.reset();
+    }
+
+    @Benchmark
+    public void part2() throws IOException {
+        Day16.part2(this.input);
+        this.input.reset();
+    }
+}

java/src/main/java/com/github/saser/adventofcode/year2016/day16/BUILD.bazel

@@ -0,0 +1,7 @@
+package(default_visibility = ["//visibility:public"])
+
+java_library(
+    name = "day16",
+    srcs = glob(["*.java"]),
+    deps = ["//java/src/main/java/com/github/saser/adventofcode:adventofcode"],
+)

java/src/main/java/com/github/saser/adventofcode/year2016/day16/Day16.java

@@ -0,0 +1,74 @@
+package com.github.saser.adventofcode.year2016.day16;
+
+import java.io.BufferedReader;
+import java.io.Reader;
+import java.util.Arrays;
+
+import com.github.saser.adventofcode.Result;
+
+public final class Day16 {
+    public static Result part1(Reader r) {
+        return solve(r, 1);
+    }
+
+    public static Result part2(Reader r) {
+        return solve(r, 2);
+    }
+
+    private static Result solve(Reader r, int part) {
+        try {
+            var state = Day16.parse(r);
+            state = Day16.generate(state, part == 1 ? 272 : 35651584);
+            var checksum = Day16.checksum(state);
+            return Result.ok(Day16.toString(checksum));
+        } catch (Exception e) {
+            e.printStackTrace();
+            return Result.err(e.getMessage());
+        }
+    }
+
+    private static boolean[] parse(Reader r) throws Exception {
+        var line = new BufferedReader(r).readLine();
+        var state = new boolean[line.length()];
+        for (var i = 0; i < line.length(); i++) {
+            state[i] = line.charAt(i) == '1';
+        }
+        return state;
+    }
+
+    private static String toString(boolean[] state) {
+        var sb = new StringBuilder(state.length);
+        for (var bit : state) {
+            sb.append(bit ? '1' : '0');
+        }
+        return sb.toString();
+    }
+
+    private static boolean[] generate(boolean[] state) {
+        var n = 1 + state.length * 2;
+        var newState = new boolean[n];
+        for (var i = 0; i < state.length; i++) {
+            newState[i] = state[i];
+            newState[n - (i + 1)] = !state[i];
+        }
+        return newState;
+    }
+
+    private static boolean[] generate(boolean[] state, int size) {
+        while (state.length < size) {
+            state = generate(state);
+        }
+        return Arrays.copyOf(state, size);
+    }
+
+    private static boolean[] checksum(boolean[] state) {
+        if (state.length % 2 == 1) {
+            return state;
+        }
+        var newState = new boolean[state.length / 2];
+        for (var i = 0; i < newState.length; i++) {
+            newState[i] = state[2 * i] == state[2 * i + 1];
+        }
+        return checksum(newState);
+    }
+}

java/src/test/java/com/github/saser/adventofcode/year2016/day16/BUILD.bazel

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+java_test(
+    name = "test",
+    srcs = glob(["*.java"]),
+    test_class = "com.github.saser.adventofcode.year2016.day16.Day16Test",
+    deps = [
+        "@maven//:junit_junit",
+        "//java/src/main/java/com/github/saser/adventofcode:adventofcode",
+        "//java/src/main/java/com/github/saser/adventofcode/year2016/day16:day16",
+    ],
+    data = ["//inputs:2016/16"],
+)

java/src/test/java/com/github/saser/adventofcode/year2016/day16/Day16Test.java

@@ -0,0 +1,30 @@
+package com.github.saser.adventofcode.year2016.day16;
+
+import java.io.FileReader;
+import java.io.IOException;
+import java.io.StringReader;
+
+import org.junit.Test;
+import org.junit.Assert;
+
+public class Day16Test {
+    @Test
+    public void part1Actual() throws IOException {
+        try (var input = new FileReader("inputs/2016/16")) {
+            var output = "10010010110011010";
+            var result = Day16.part1(input);
+            Assert.assertEquals("no error", "", result.error);
+            Assert.assertEquals("correct output", output, result.answer);
+        }
+    }
+
+     @Test
+     public void part2Actual() throws IOException {
+         try (var input = new FileReader("inputs/2016/16")) {
+             var output = "01010100101011100";
+             var result = Day16.part2(input);
+             Assert.assertEquals("no error", "", result.error);
+             Assert.assertEquals("correct output", output, result.answer);
+         }
+     }
+}