Longest common subsequence: Difference between revisions

=={{header|C sharp|C#}}==

<lang csharp>using System;

namespace LCS

{

class Program

{

static void Main(string[] args)

{

string word1 = "thisisatest";

string word2 = "testing123testing";

Console.WriteLine(lcsBack(word1, word2));

Console.ReadKey();

}

public static string lcsBack(string a, string b)

{

string aSub = a.Substring(0, (a.Length - 1 < 0) ? 0 : a.Length - 1);

string bSub = b.Substring(0, (b.Length - 1 < 0) ? 0 : b.Length - 1);

if (a.Length == 0 || b.Length == 0)

return "";

else if (a[a.Length - 1] == b[b.Length - 1])

return lcsBack(aSub, bSub) + a[a.Length - 1];

else

{

string x = lcsBack(a, bSub);

string y = lcsBack(aSub, b);

return (x.Length > y.Length) ? x : y;

}

}

}

}</lang>