[gbrainy] Fixes #612652

[Jordi Mas <jmas src gnome org>]

commit 4fe30f016a79dc14c1166fbc3d2a9d3375b4c123
Author: Jordi Mas <jmas softcatala org>
Date:   Fri Mar 12 17:20:34 2010 +0100

    Fixes #612652

 src/Games/Logic/PuzzleOstracism.cs |   32 +++++++++++++++++++++-----------
 1 files changed, 21 insertions(+), 11 deletions(-)
---
diff --git a/src/Games/Logic/PuzzleOstracism.cs b/src/Games/Logic/PuzzleOstracism.cs
index 9d74022..8cd9714 100644
--- a/src/Games/Logic/PuzzleOstracism.cs
+++ b/src/Games/Logic/PuzzleOstracism.cs
@@ -103,20 +103,30 @@ namespace gbrainy.Games.Logic
 				break;
 			case GameType.Numbers:
 			{
-				int num;
-				int [] seeds = {25, 26, 28, 30, 21, 18, 21, 22};
+				int num, evens;
+				int [] seeds = {25, 26, 28, 30, 18, 21, 22};
 				ArrayListIndicesRandom random_seeds = new ArrayListIndicesRandom (seeds.Length);
-				random_seeds.Initialize ();
 
-				equations = new string [max_equations];
-				for (int i = 0; i < max_equations - 1; i++)
+				// Make sure that one of the numbers only is not even or odd to avoid
+				// this rationale as valid answer too
+				do
 				{
-					num = seeds [random_seeds [i]];
-					equations [i] = num.ToString () + (num * num).ToString ();
-				}
-
-				num = seeds [random_seeds [max_equations - 1]];
-				equations [max_equations - 1] = num.ToString () + ((num * num) -  20).ToString ();
+					evens = 0;
+					random_seeds.Initialize ();
+
+					equations = new string [max_equations];
+					for (int i = 0; i < max_equations - 1; i++)
+					{
+						num = seeds [random_seeds [i]];
+						equations [i] = num.ToString () + (num * num).ToString ();
+						if (num % 2 == 0) evens++;
+					}
+					num = seeds [random_seeds [max_equations - 1]];
+					equations [max_equations - 1] = num.ToString () + ((num * num) -  20).ToString ();
+
+					if (num % 2 == 0) evens++;
+
+				} while (evens <= 1 || max_equations - evens <= 1 /* odds */);
 				break;
 			}
 			default: