/// <summary>
/// Returns the longest common string of the two specified strings.
/// </summary>
/// <param name="s">one string</param>
/// <param name="t">the other string</param>
/// <returns>the longest common string that appears as a substring
/// in both <c>s</c> and <c>t</c>; the empty string
/// if no such string</returns>
///
public static string Lcs(string s, string t)
{
SuffixArray suffix1 = new SuffixArray(s);
SuffixArray suffix2 = new SuffixArray(t);
// find longest common substring by "merging" sorted suffixes
string lcs = "";
int i = 0, j = 0;
while (i < s.Length && j < t.Length)
{
int p = suffix1.Index(i);
int q = suffix2.Index(j);
string x = lcp(s, p, t, q);
if (x.Length > lcs.Length)
{
lcs = x;
}
if (compare(s, p, t, q) < 0)
{
i++;
}
else
{
j++;
}
}
return(lcs);
}
public static void MainTest(string[] args)
{
TextInput StdIn = new TextInput();
Regex WhiteSpace = new Regex(@"[\s]+", RegexOptions.Compiled);
string s = StdIn.ReadAll().Trim();
s = WhiteSpace.Replace(s, " ");
SuffixArray suffix = new SuffixArray(s.Trim());
Console.WriteLine(" i ind lcp rnk select");
Console.WriteLine("---------------------------");
for (int i = 0; i < s.Length; i++)
{
int index = suffix.Index(i);
string ith = "\"" + s.Substring(index, Math.Min(index + 50, s.Length) - index) + "\"";
Debug.Assert(s.Substring(index).Equals(suffix.Select(i)));
int rank = suffix.Rank(s.Substring(index));
if (i == 0)
{
Console.WriteLine("{0,3} {1,3} {2,3} {3,3} {4}", i, index, "-", rank, ith);
}
else
{
int lcp = suffix.Lcp(i);
Console.WriteLine("{0,3} {1,3} {2,3} {3,3} {4}", i, index, lcp, rank, ith);
}
}
}
public static void MainTest(string[] args)
{
TextInput StdIn = new TextInput();
Regex WhiteSpace = new Regex(@"[\s]+", RegexOptions.Compiled);
string text = StdIn.ReadAll();
text = WhiteSpace.Replace(text, " ");
SuffixArray suffix = new SuffixArray(text.Trim());
//Console.WriteLine(text);
Console.WriteLine("'" + LongestRepeatedSubstring.Lrs(text) + "'");
}
public static void MainTest(string[] args)
{
TextInput StdIn = new TextInput();
Regex WhiteSpace = new Regex(@"[\s]+", RegexOptions.Compiled);
string s = StdIn.ReadAll().Trim();
s = WhiteSpace.Replace(s, " ");
SuffixArray suffix2 = new SuffixArray(s);
SuffixArrayX suffix1 = new SuffixArrayX(s);
bool check = true;
for (int i = 0; check && i < s.Length; i++)
{
if (suffix1.Index(i) != suffix2.Index(i))
{
Console.WriteLine("suffix1(" + i + ") = " + suffix1.Index(i));
Console.WriteLine("suffix2(" + i + ") = " + suffix2.Index(i));
string ith = "\"" + s.Substring(suffix1.Index(i), Math.Min(suffix1.Index(i) + 50, s.Length) - suffix1.Index(i)) + "\"";
string jth = "\"" + s.Substring(suffix2.Index(i), Math.Min(suffix2.Index(i) + 50, s.Length) - suffix2.Index(i)) + "\"";
Console.WriteLine(ith);
Console.WriteLine(jth);
check = false;
}
}
Console.WriteLine(" i ind lcp rnk select");
Console.WriteLine("---------------------------");
for (int i = 0; i < s.Length; i++)
{
int index = suffix2.Index(i);
string ith = "\"" + s.Substring(index, Math.Min(index + 50, s.Length) - index) + "\"";
Debug.Assert(s.Substring(index).Equals(suffix2.Select(i)));
int rank = suffix2.Rank(s.Substring(index));
if (i == 0)
{
Console.Write("{0,3} {1,3} {2,3} {3,3} {4}\n", i, index, "-", rank, ith);
}
else
{
// int lcp = suffix.lcp(suffix2.index(i), suffix2.index(i-1));
int lcp = suffix2.Lcp(i);
Console.Write("{0,3} {1,3} {2,3} {3,3} {4}\n", i, index, lcp, rank, ith);
}
}
}
/// <summary>
/// Returns the longest repeated substring of the specified string.</summary>
/// <param name="text">the string</param>
/// <returns>the longest repeated substring that appears in <c>text</c>;
/// the empty string if no such string</returns>
///
public static string Lrs(string text)
{
int N = text.Length;
SuffixArray sa = new SuffixArray(text);
string lrs = "";
for (int i = 1; i < N; i++)
{
int length = sa.Lcp(i);
if (length > lrs.Length)
{
lrs = text.Substring(sa.Index(i), sa.Index(i) + length - sa.Index(i));
}
}
return(lrs);
}
public static void MainTest(string[] args)
{
Regex WhiteSpace = new Regex(@"[\s]+", RegexOptions.Compiled);
TextInput input = new TextInput(args[0]);
int context = int.Parse(args[1]);
// read in text
string text = input.ReadAll();
text = WhiteSpace.Replace(text, " ");
int N = text.Length;
// build suffix array
SuffixArray sa = new SuffixArray(text);
TextInput StdIn = new TextInput();
// find all occurrences of queries and give context
while (StdIn.HasNextLine())
{
string query = StdIn.ReadLine();
for (int i = sa.Rank(query); i < N; i++)
{
int from1 = sa.Index(i);
int to1 = Math.Min(N, from1 + query.Length);
if (!query.Equals(text.Substring(from1, to1 - from1)))
{
break;
}
int from2 = Math.Max(0, sa.Index(i) - context);
int to2 = Math.Min(N, sa.Index(i) + context + query.Length);
Console.WriteLine(text.Substring(from2, to2 - from2));
}
Console.WriteLine();
}
}
