private void lengthLCS()
	{
		// Subproblems are encountered in the increasing order of their size if
		// we proceed in the row major order or in column major order
		for (int i = 1; i < X.length(); i++)
			for (int j = 1; j < Y.length(); j++)
				if (X.charAt(i) == Y.charAt(j))
					len[i][j] = len[i - 1][j - 1] + 1;
				else
				{
					if (len[i - 1][j] >= len[i][j - 1])
					{
						len[i][j] = len[i - 1][j];
					}
					else
					{
						len[i][j] = len[i][j - 1];
					}
				}
	}