private static int BruteForce(char[] data)
{
for (int i = data.Length; i > 1; i--)
{
for (int j = 0; j <= data.Length - i; j++)
{
int diff = 0;
for (int k = j; k < j + i; k++)
{
if (LettersAndNumbers.IsNumber(data[k]))
{
diff++;
}
else
{
diff--;
}
}
if (diff == 0)
{
return(i);
}
}
}
return(0);
}
private static int HashTable(char[] data)
{
int[] diffs = new int[data.Length];
int diff = 0;
for (int i = 0; i < data.Length; i++)
{
if (LettersAndNumbers.IsNumber(data[i]))
{
diff++;
}
else
{
diff--;
}
diffs[i] = diff;
}
HashTable <int, int> hashTable = new HashTable <int, int>();
hashTable[0] = -1;
int max = 0;
for (int i = 0; i < diffs.Length; i++)
{
if (hashTable.Contains(diffs[i]))
{
max = Math.Max(max, i - hashTable[diffs[i]]);
}
else
{
hashTable[diffs[i]] = i;
}
}
return(max);
}