private static void findLCS(Data[,,,] mtx, char[][] seq, int[] len)
{
int[] ind = new int[RANK];
for (ind[0] = 1; ind[0] < len[0]; ind[0]++)
{
for (ind[1] = 1; ind[1] < len[1]; ind[1]++)
{
for (ind[2] = 1; ind[2] < len[2]; ind[2]++)
{
for (ind[3] = 1; ind[3] < len[3]; ind[3]++)
{
bool eqFlag = true;
for (int i = 1; i < RANK; i++)
{
if (seq[i][ind[i] - 1] != seq[i - 1][ind[i - 1] - 1])
{
eqFlag = false;
break;
}
}
if (eqFlag)
{
mtx[ind[0], ind[1], ind[2], ind[3]].c =
mtx[ind[0] - 1, ind[1] - 1, ind[2] - 1, ind[3] - 1].c + 1;
mtx[ind[0], ind[1], ind[2], ind[3]].b = RANK;
continue;
}
int R = -1;
int M = -1;
for (int i = 0; i < RANK; i++)
{
ind[i]--;
if (mtx[ind[0], ind[1], ind[2], ind[3]].c > M)
{
R = i;
M = mtx[ind[0], ind[1], ind[2], ind[3]].c;
}
ind[i]++;
}
if (R < 0 || M < 0)
throw new Exception();
mtx[ind[0], ind[1], ind[2], ind[3]].c = M;
mtx[ind[0], ind[1], ind[2], ind[3]].b = R;
}
}
}
}
}
private static String buildLCS(Data[,,,] mtx, char[] X, int[] ind)
{
for (int i = 0; i < RANK; i++)
if (ind[i] == 0) return "";
int L = mtx[ind[0], ind[1], ind[2], ind[3]].b;
if (L == RANK)
{
for (int i = 0; i < RANK; i++)
ind[i]--;
int idx = ind[0];
return buildLCS(mtx, X, ind) + X[idx];
}
if (L >= 0 && L < RANK)
{
ind[L]--;
return buildLCS(mtx, X, ind);
}
throw new Exception();
}
private static int Main()
{
Console.WriteLine("Test searches for longest common subsequence of 4 strings\n\n");
String[] str = new String[RANK] {
"The Sun has left his blackness",
"and has found a fresher morning",
"and the fair Moon rejoices",
"in the clear and cloudless night"
};
int[] len = new int[RANK];
char[][] seq = new char[RANK][];
for (int i = 0; i < RANK; i++)
{
len[i] = str[i].Length + 1;
seq[i] = str[i].ToCharArray();
}
Data[,,,] mtx = new Data[len[0], len[1], len[2], len[3]];
findLCS(mtx, seq, len);
for (int i = 0; i < RANK; i++)
len[i]--;
if ("n ha es" == buildLCS(mtx, seq[0], len))
{
Console.WriteLine("Test passed");
return 100;
}
else
{
Console.WriteLine("Test failed.");
return 0;
}
}
