Question

I am working through problem set 3 and just finished the third part: http://codepad.org/nMGYIwe4. My first question is, does it look correct? I have also done what I think I was supposed to do on part 4: http://codepad.org/EF1Fv6hT. I am confused because the output I am getting for part 3 and part 4 is the same. I suppose if I try different test strings I may get differing results. I will try that now. The reason I am asking now though, is because I am not really sure what part 4 was asking. Am I on the right track? Thanks in advance. I am working through problem set 3 and just finished the third part: http://codepad.org/nMGYIwe4. My first question is, does it look correct? I have also done what I think I was supposed to do on part 4: http://codepad.org/EF1Fv6hT. I am confused because the output I am getting for part 3 and part 4 is the same. I suppose if I try different test strings I may get differing results. I will try that now. The reason I am asking now though, is because I am not really sure what part 4 was asking. Am I on the right track? Thanks in advance. @MIT 6.00 Intro Co…

Answer 1

Unfortunately those links give 404 errors. Can you post your code again?

Answer 2

Ps3 part3: http://codepad.org/s65QKWGi
Ps4 part4: http://codepad.org/vy30P1mV

Answer 3

Part 4 is asking you to use your results from part 3 (where matches would be if one letter was different), but then subtract out the places where exact matches are. When you search with key 'atgc' part 3 will still find places in target that were 'atgc'. Part 4 wants to ignore those exact matches. So, it's asking for places where there is "exactly one substitution," not "at most one substitution."