Advent of Code 2021 - Day 1

Author: CodingNagger

.gitignore

@@ -1 +1,3 @@
-target/
+target/
+.idea
+*.iml

.vscode/launch.json

@@ -18,6 +18,6 @@ mvn clean test
 
 Last year I ran a [cruise log for my 25 days competing in the Advent of Code](https://www.codingnagger.com/tag/advent-of-code-2020/) and decided I would at least try to do the same this year.
 
-
+- [The Advent of Code 2021 Day 1 log, starting slow](https://www.codingnagger.com/2021/12/01/the-advent-of-code-2021-day-1-log-starting-slow/)
 
 

.vscode/settings.json

@@ -25,6 +25,12 @@
       <version>4.11</version>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>org.assertj</groupId>
+      <artifactId>assertj-core</artifactId>
+      <version>3.21.0</version>
+      <scope>test</scope>
+    </dependency>
   </dependencies>
 
   <build>

README.md

@@ -1,27 +1,27 @@
 package com.codingnagger;
 
-import java.io.IOException;
-
+import com.codingnagger.days.Day;
+import com.codingnagger.days.Day1;
 import com.codingnagger.utils.InputLoader;
 
+import java.io.IOException;
+import java.util.List;
+
 /**
  * Hello world!
- *
  */
-public class App 
-{
-    public static void main( String[] args ) throws IOException
-    {
-        System.out.println( "Advent of Code 2021" );
+public class App {
+    public static void main(String[] args) throws IOException {
+        System.out.println("Advent of Code 2021");
 
-        Iterable<String> input = new InputLoader().Load("day1.txt");
+        List<String> input = new InputLoader().Load("day1.txt");
 
-        // Day day = new Day1();
+        Day day = new Day1();
 
-        System.out.println( "Part 1:" );
-        // System.out.println(day1.partOne(input));
+        System.out.println("Part 1:");
+        System.out.println(day.partOne(input));
 
-        System.out.println( "Part 2:" );
-        // System.out.println(day1.partTwo(input));
+        System.out.println("Part 2:");
+        System.out.println(day.partTwo(input));
     }
 }

pom.xml

@@ -1,6 +1,9 @@
 package com.codingnagger.days;
 
+import java.util.List;
+
 public interface Day {
-  public String Part1(Iterable<String> input);
-  public String Part2(Iterable<String> input);
+    String partOne(List<String> input);
+
+    String partTwo(List<String> input);
 }

src/main/java/com/codingnagger/App.java

@@ -0,0 +1,42 @@
+package com.codingnagger.days;
+
+import java.util.List;
+
+import static com.codingnagger.utils.InputConverter.convertToIntegers;
+
+public class Day1 implements Day {
+
+    @Override
+    public String partOne(List<String> input) {
+        return computeIncreases(input, 1);
+    }
+
+    @Override
+    public String partTwo(List<String> input) {
+        return computeIncreases(input, 3);
+    }
+
+    private String computeIncreases(List<String> input, int slidingWindowSize) {
+        List<Integer> integerInput = convertToIntegers(input);
+        int increaseCount = 0;
+        int previous = slidingWindowSum(integerInput, 0, slidingWindowSize);
+
+        for (int i = 1; i < integerInput.size() - slidingWindowSize + 1; i++) {
+            int value = slidingWindowSum(integerInput, i, slidingWindowSize);
+
+            if (value > previous) {
+                increaseCount++;
+            }
+            previous = value;
+        }
+        return "" + increaseCount;
+    }
+
+    private int slidingWindowSum(List<Integer> integerInput, int index, int slidingWindowSize) {
+        int sum = 0;
+        for (int i = 0; i < slidingWindowSize; i++) {
+            sum += integerInput.get(i + index);
+        }
+        return sum;
+    }
+}

src/main/java/com/codingnagger/days/Day.java

@@ -0,0 +1,10 @@
+package com.codingnagger.utils;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class InputConverter {
+    public static List<Integer> convertToIntegers(List<String> input) {
+        return input.stream().map(Integer::parseInt).collect(Collectors.toList());
+    }
+}

src/main/java/com/codingnagger/days/Day1.java

@@ -6,7 +6,15 @@
 import java.util.List;
 
 public class InputLoader {
-  public List<String> Load(String filename) throws IOException {
-    return Files.readAllLines(Paths.get("src","main","resources", filename));
-  }
+    public static List<String> Load(String filename) throws IOException {
+        return Load("main", filename);
+    }
+
+    public static List<String> LoadTest(String filename) throws IOException {
+        return Load("test", filename);
+    }
+
+    public static List<String> Load(String resourcesParent, String filename) throws IOException {
+        return Files.readAllLines(Paths.get("src", resourcesParent, "resources", filename));
+    }
 }