public (int begin, int end) Find(string query)
{
var p = new StringView(query);
int l = LowerBound(p, 0, CharacterCount);
int u = UpperBound(p, 0, CharacterCount);
return(l, u);
}
private int LowerBound(StringView pattern, int start, int end)
{
while (start < end)
{
int mid = start + (end - start) / 2;
var suffix = GetSuffix(SA[mid], pattern.Length);
if (Algorithm.LexicographicalCompare(suffix, pattern))
{
start = mid + 1;
}
else
{
end = mid;
}
}
return(start);
}
public static bool LexicographicalCompare(StringView a, StringView b)
{
int first1 = a.Offset;
int first2 = b.Offset;
int last1 = a.Offset + a.Length;
int last2 = b.Offset + b.Length;
while (first1 != last1)
{
if (first2 == last2 || b.AtAbsolute(first2) < a.AtAbsolute(first1))
{
return(false);
}
if (a.AtAbsolute(first1) < b.AtAbsolute(first2))
{
return(true);
}
++first1;
++first2;
}
return(first2 != last2);
}