feat: solve day 9 part 2

Author: Flashky

src/main/java/com/adventofcode/flashk/day09/DiskDefragmenter.java

@@ -0,0 +1,56 @@
+package com.adventofcode.flashk.day09;
+
+import java.util.ArrayDeque;
+import java.util.ArrayList;
+import java.util.Deque;
+import java.util.List;
+
+public class DiskDefragmenter {
+
+    private final Deque<File> files = new ArrayDeque<>();
+    private final List<Unallocated> unallocateds = new ArrayList<>();
+
+    public DiskDefragmenter(List<String> inputs){
+
+        char[] diskMap = inputs.get(0).toCharArray();
+        int fileId = 0;
+        int blockIndex = 0;
+
+        for(int i = 0; i < diskMap.length; i++) {
+
+            int blockSize = Character.getNumericValue(diskMap[i]);
+
+            if(i % 2 == 0) {
+                files.add(new File(fileId++, blockIndex, blockSize));
+            } else {
+                unallocateds.add(new Unallocated(blockIndex, blockSize));
+            }
+
+            blockIndex += blockSize;
+
+        }
+
+    }
+
+    public long solve() {
+        long result = 0;
+        while(!files.isEmpty()) {
+            File file = files.pollLast();
+            result += reallocate(file);
+
+        }
+        return result;
+    }
+
+    private long reallocate(File file) {
+
+        for(Unallocated unallocated : unallocateds) {
+            if(unallocated.canAllocate(file)) {
+                unallocated.allocate(file);
+                break;
+            }
+        }
+
+        return file.checksum();
+    }
+}

src/main/java/com/adventofcode/flashk/day09/DiskFragmenter.java

@@ -58,6 +58,10 @@ public long solveA() {
 
     }
 
+    public long solveB() {
+
+        return 0;
+    }
     /*
     private long checksum() {
         long result = 0;

src/main/java/com/adventofcode/flashk/day09/File.java

@@ -0,0 +1,36 @@
+package com.adventofcode.flashk.day09;
+
+import lombok.Getter;
+
+
+public class File {
+
+    private static int maxIdFile = 0;
+
+    private final int id;
+    @Getter
+    private int startBlockIndex;
+    private int endBlockIndex;
+    @Getter
+    private final int size;
+
+    public File(int fileId, int startBlockIndex, int size) {
+        this.id = fileId;
+        this.startBlockIndex = startBlockIndex;
+        this.endBlockIndex = startBlockIndex + size - 1;
+        this.size = size;
+    }
+
+    public void move(int startBlockIndex) {
+        this.startBlockIndex = startBlockIndex;
+        this.endBlockIndex = startBlockIndex + size - 1;
+    }
+
+    public long checksum() {
+        long result = 0;
+        for(int i = startBlockIndex; i <= endBlockIndex; i++) {
+            result += (long) id * i;
+        }
+        return result;
+    }
+}

src/main/java/com/adventofcode/flashk/day09/Unallocated.java

@@ -0,0 +1,29 @@
+package com.adventofcode.flashk.day09;
+
+import lombok.Getter;
+
+public class Unallocated {
+
+    private int startBlockIndex;
+    private int size;
+
+    public Unallocated(int startBlockIndex, int size) {
+        this.startBlockIndex = startBlockIndex;
+        this.size = size;
+    }
+
+    public boolean canAllocate(File file) {
+        return this.size >= file.getSize() && this.startBlockIndex <= file.getStartBlockIndex();
+    }
+
+    public void allocate(File file) {
+
+        if(canAllocate(file)) {
+            file.move(this.startBlockIndex);
+            this.startBlockIndex += file.getSize();
+            this.size -= file.getSize();
+        }
+    }
+
+}
+

src/test/java/com/adventofcode/flashk/day09/Day09Test.java

@@ -81,8 +81,8 @@ public void testSolvePart2Sample() {
 
 		// Read input file
 		List<String> inputs = Input.readStringLines(INPUT_FOLDER, TestFilename.INPUT_FILE_SAMPLE);
-		DiskFragmenter diskFragmenter = new DiskFragmenter(inputs);
-		assertEquals(2858L, diskFragmenter.solveB());
+		DiskDefragmenter diskDefragmenter = new DiskDefragmenter(inputs);
+		assertEquals(2858L, diskDefragmenter.solve());
 	}
 
 	@Test
@@ -95,9 +95,9 @@ public void testSolvePart2Input() {
 		// Read input file
 		List<String> inputs = Input.readStringLines(INPUT_FOLDER, TestFilename.INPUT_FILE);
 
+		DiskDefragmenter diskDefragmenter = new DiskDefragmenter(inputs);
 
-		System.out.println("Solution: ");
-		assertEquals(0L, 0L);
+		assertEquals(6335972980679L, diskDefragmenter.solve());
 
 	}