Day2

Day1.cs

@@ -1,4 +1,4 @@
-#define Day1
+// #define Day1
 #if Day1
 var scans = File.ReadAllLines("day1/input").Select(int.Parse).ToList();
 Console.WriteLine(Enumerable.Range(1, scans.Count - 1).Count(i => scans[i - 1] < scans[i]));

Day2.cs

@@ -1,4 +1,43 @@
-// #define Day2
+#define Day2
 #if Day2
-var toBeDefined = File.ReadAllLines("day2/input");
+long f = 0;
+long d = 0;
+var linesSplit = File.ReadAllLines("day2/input")
+    .Select(l => l.Split(" "))
+    .Select(lineParts => new { op = lineParts[0], x = long.Parse(lineParts[1]) })
+    .ToList();
+
+linesSplit.ForEach(v => {
+    switch (v.op) {
+        case "down":
+            d += v.x;
+            break;
+        case "up":
+            d -= v.x;
+            break;
+        default:
+            f += v.x;
+            break;
+    }
+});
+Console.WriteLine(f * d);
+
+f = 0;
+d = 0;
+long aim = 0;
+linesSplit.ForEach(v => {
+    switch (v.op) {
+        case "down":
+            aim += v.x;
+            break;
+        case "up":
+            aim -= v.x;
+            break;
+        default:
+            f += v.x;
+            d += aim * v.x;
+            break;
+    }
+});
+Console.WriteLine(f * d);
 #endif