Still lost

09/code.go

@@ -83,6 +83,74 @@ func part1(diskMap []int) int64 {
 	return calculateChecksum(compacted)
 }
 
+func findFile(disk []int, id, end int) int {
+	for i := end; i > 0; i-- {
+		if disk[i] != id {
+			return i + 1
+		}
+	}
+
+	return -1
+}
+
+func findFree(disk []int, start, end, goal int) (int, int) {
+	var freeStart, freeEnd int
+	for i := start; i < end; i++ {
+		if disk[i] == -1 {
+			if freeStart <= 0 {
+				freeStart = i
+				for j := freeStart + 1; j < freeStart+goal; j++ {
+					if disk[i] != -1 {
+						freeStart = -1
+						i = j
+						break
+					}
+				}
+
+				if freeStart > 0 {
+					return freeStart, freeStart + goal
+				}
+			}
+		}
+	}
+
+	return freeStart, freeEnd
+}
+
+func defrag(diskMap []int) []int {
+	free, disk := getDisk(diskMap)
+	end := len(disk) - 1
+
+	for i := end; i > free; i-- {
+		if disk[i] > 0 {
+			fileStart := findFile(disk, disk[i], i)
+			if fileStart > 0 {
+				freeStart, freeEnd := findFree(disk, free, fileStart, i-fileStart+1)
+				fmt.Println(i, disk[i], freeStart, freeEnd)
+				if freeStart > 0 && freeEnd > 0 && freeStart < freeEnd {
+					for k := freeStart; k < freeEnd; k++ {
+						disk[k] = disk[i]
+					}
+
+					for k := fileStart; k <= i; k++ {
+						disk[k] = -1
+					}
+
+					i = fileStart
+				}
+			}
+		}
+	}
+
+	return disk
+}
+
+func part2(diskMap []int) int64 {
+	fmt.Println(defrag(diskMap))
+
+	return 0
+}
+
 func main() {
 	if len(os.Args) < 2 {
 		log.Fatal("You need to specify a file!")
@@ -95,4 +163,5 @@ func main() {
 
 	diskMap := getDiskMap(data)
 	fmt.Println("Part1:", part1(diskMap))
+	fmt.Println("Part2:", part2(diskMap))
 }