Unique Prefixes

UniquePrefix.cs

string[] words = new string[]
{"zebra","beard","duck","zest", "ducklin", "bearcat","dumb","beautiful","zebracrossing"};
//{ "zebra", "dog", "duck", "zimbawae", "zest","god","dove", "dig","got","dumb"};

Array.Sort(words);

Func<string, string, int> DiffersAt = (a, b) =>
  {
  	  int m = a.Length;
	  int n = b.Length;
	  int length = Math.Min(m, n);

	  for (int i = 0; i < length; i++)
	  {
	  	if (a[i] != b[i])
			  return i;
	  }
	  return length;
  };
List<KeyValuePair<string, string>> pairs =
   new List<KeyValuePair<string, string>>();
for (int i = 0; i < words.Length - 1; i++)
{
	int mismatchAt = DiffersAt(words[i], words[i + 1]);
    
	pairs.Add(new KeyValuePair<string, string>(words[i], 
	           words[i].Substring(0, mismatchAt + 1 >= 
			         words[i].Length? words[i].Length : mismatchAt  + 1)));
	pairs.Add(new KeyValuePair<string, string>(words[i + 1], 
	           words[i + 1].Substring(0, mismatchAt + 1>= 
			         words[i+1].Length? words[i+1].Length : mismatchAt  + 1)));
}
Dictionary<string, string> wordHashMap = 
       new Dictionary<string, string>();
foreach (var pair in pairs)
{
	if (!wordHashMap.ContainsKey(pair.Key))
	{
		wordHashMap.Add(pair.Key, pair.Value);
	}
	else
	{
		if(wordHashMap[pair.Key].Length < pair.Value.Length)
			wordHashMap[pair.Key] = pair.Value;
			
	}
}

wordHashMap.Dump("Final Mapping");