From b0e2db6a96c394cc16fec1fe164a47dc42dee031 Mon Sep 17 00:00:00 2001
From: Greg Edwards <edwardsgreg@gmail.com>
Date: Tue, 31 Mar 2015 02:05:41 -0400
Subject: [PATCH] Added reverse experience formula. (untested)

---
 library/Structures/PokemonBase.cs | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/library/Structures/PokemonBase.cs b/library/Structures/PokemonBase.cs
index 61baf234..3f273b4f 100644
--- a/library/Structures/PokemonBase.cs
+++ b/library/Structures/PokemonBase.cs
@@ -222,6 +222,34 @@ namespace PkmnFoundations.Structures
             throw new ArgumentException("gr");
         }
 
+        public static int LevelAt(int experience, GrowthRates gr)
+        {
+            if (experience < 0) throw new ArgumentOutOfRangeException("experience");
+
+            int minLevel = 1, maxLevel = 100;
+            int minExp = ExperienceAt(1, gr), maxExp = ExperienceAt(100, gr);
+
+            while (1 < 2)
+            {
+                if (maxExp <= experience) return maxLevel;
+                if (minLevel + 1 >= maxLevel) return minLevel;
+
+                int midLevel = (minLevel + maxLevel) >> 1;
+                int midExp = ExperienceAt(midLevel, gr);
+
+                if (experience >= midExp)
+                {
+                    minLevel = midLevel;
+                    minExp = midExp;
+                }
+                else
+                {
+                    maxLevel = midLevel;
+                    maxExp = midExp;
+                }
+            }
+        }
+
         private static int ExperienceAt_Slow(int level)
         {
             int cube = level * level * level;