Greedy Motif Search Using Probability Matrices
Assuming you're talking about Implement GreedyMotifSearch from Rosalind, while I haven't actually finished this particular one, I've got an idea why TTC,ATC,TTC,ATC,TTC doesn't work. Here's my explanation from the "Questions" section of that problem:


  The profile is created from the first kmers in each string, and the most likely string from those is CAG. The answers will generally be similar to this.


I've been trying to do Rosalind by only using the information provided in the questions; this is one of the many problems where there wasn't enough information in the Question for me to arrive at a correct solution when I tried it. It's possible that the debug datasets were added to this question since I last looked at it, as they seem to describe this situation:

TEST DATASET 1:

Input:

3 4
GCCCAA
GGCCTG
AACCTA
TTCCTT


Output:

GCC
GCC
AAC
TTC



  This dataset checks that your code always picks the first-occurring Profile-most Probable k-mer in a given sequence of Dna. In the first sequence (“GCCCAA”), “GCC” and “CCA” are both Profile-most Probable k-mers. However, you must return “GCC” since it occurs earlier than “CCA”. Thus, if the first sequence of your output is “CCA”, this test case fails your code.