Exercise 1.5: Longest common substring
Write a function that takes two sequences and returns the longest common substring. A substring is a contiguous portion of a string. For example:
Substrings of ATGCATAT
:
TGCA
T
TAT
Not substrings of ATGCATAT
:
AGCA # Skipped T
CCATA # Added another C
Hello, world. # Has nothing to do with the input sequence
There may be more than one longest common substring; you only need to return one of them.
The call signature of the function should be
longest_common_substring(s1, s2)
Here are some return values you should get.
Function call |
Result |
---|---|
|
|
|
|
|
|