feat(*): Add 2021-02 files

2021/02/Program.cs

@@ -0,0 +1,56 @@
+// Part 1
+string[] lines = File.ReadAllLines("input.txt");
+
+int horizontalPosition = 0;
+int verticalPosition = 0;
+
+foreach (string line in lines)
+{
+    string[] parts = line.Split(' ');
+
+    if (parts[0] == "forward")
+    {
+        horizontalPosition += Int32.Parse(parts[1]);
+    }
+    else if (parts[0] == "down")
+    {
+        verticalPosition += Int32.Parse(parts[1]);
+    }
+    else if (parts[0] == "up")
+    {
+        verticalPosition -= Int32.Parse(parts[1]);
+    }
+}
+
+Console.WriteLine($"Final position: {horizontalPosition},{verticalPosition}");
+
+Console.WriteLine($"Multiplied together, that is: {horizontalPosition * verticalPosition}");
+
+
+// Part 2
+int newHorizontalPosition = 0;
+int newVerticalPosition = 0;
+int aim = 0;
+
+foreach (string line in lines)
+{
+    string[] parts = line.Split(' ');
+
+    if (parts[0] == "forward")
+    {
+        newHorizontalPosition += Int32.Parse(parts[1]);
+        newVerticalPosition += (aim * Int32.Parse(parts[1]));
+    }
+    else if (parts[0] == "down")
+    {
+        aim += Int32.Parse(parts[1]);
+    }
+    else if (parts[0] == "up")
+    {
+        aim -= Int32.Parse(parts[1]);
+    }
+}
+
+Console.WriteLine($"Final position: {newHorizontalPosition},{newVerticalPosition}");
+
+Console.WriteLine($"Multiplied together, that is: {newHorizontalPosition * newVerticalPosition}");