private static Tuple <int, int> Broken2Internal(int m, char[] text, int start, int end, out int result)
{
if (start >= end)
{
result = 0;
return(Tuple.Create(0, 0));
}
var substring = new string(text).Substring(start, end - start + 1);
var frequencyMap = new FrequencyMap(substring);
//Console.WriteLine($"Count: {frequencyMap.Count}\tLength: {end - start + 1}\t'{substring}'");
if (frequencyMap.Count <= m)
{
result = end - start + 1;
return(Tuple.Create(start, end));
}
int mid = (start + end) / 2;
int length1;
int length2;
int length3;
var result1 = Broken2Internal(m, text, start, mid, out length1);
var result2 = Broken2Internal(m, text, mid + 1, end, out length2);
var result3 = Broken2Internal(m, text, result1.Item2 + 1, result2.Item1 - 1, out length3);
var max = Math.Max(length1, Math.Max(length2, length3));
result = max;
return(length1 == max ? result1 : (length2 == max ? result2 : result3));
}
private static int Broken3(int m, string text)
{
var frequencyMap = new FrequencyMap();
var n = text.Length;
var start = 0;
var end = 0;
var result = 0;
while (end < n)
{
frequencyMap.Add(text[end]);
if (frequencyMap.Count <= m)
{
end++;
continue;
}
result = Math.Max(result, end - start);
frequencyMap.Remove(text[start++]);
frequencyMap.Remove(text[end]);
}
return(Math.Max(result, end - start));
}
