Using exceptions (just for kicks)

Author: Rafael Cunha de Almeida

Nsteps.cs

@@ -3,7 +3,7 @@
 public class Nsteps {
     public static long CoordsToNumber(long x, long y) {
         if (y != (x-2) && y != x) {
-            return -1;
+            throw new ArgumentOutOfRangeException();
         }
         if (x % 2 == 0) {
             return x + y;
@@ -16,11 +16,11 @@ public static void Main() {
         int lines = Convert.ToInt32(Console.ReadLine());
         while (lines-- > 0) {
             string[] tuple = Console.ReadLine().Split(' ');
-            long number = CoordsToNumber(Convert.ToInt64(tuple[0]), Convert.ToInt64(tuple[1]));
-            if (number < 0)  {
-                Console.WriteLine("No Number");
-            } else {
+            try {
+                long number = CoordsToNumber(Convert.ToInt64(tuple[0]), Convert.ToInt64(tuple[1]));
                 Console.WriteLine(number);
+            } catch (ArgumentOutOfRangeException) {
+                Console.WriteLine("No Number");
             }
         }
     }