Created
July 8, 2017 18:30
-
-
Save paulocheque/d3222ab37959f711f454a15048177dc8 to your computer and use it in GitHub Desktop.
Find a seq in a list
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
def find_seq(seq, alist): | |
''' | |
Find the sequence @seq in the list @alist. | |
@seq: a list or tuple with size `m`. | |
@alist: a list or tuple with size `n`. | |
@return: True if @alist contains @seq, False otherwise. | |
Complexity: `O((n-m) * m) = O(n * m)` | |
''' | |
for index, item in enumerate(alist): # O(n) | |
sublist = alist[index:index+len(seq)] | |
if len(sublist) < len(seq): | |
break | |
if seq == sublist: # O(m) | |
return True | |
return False | |
# Tests | |
assert find_seq([], [1, 3, 4]) == True | |
assert find_seq([4], [1, 3, 4]) == True | |
assert find_seq([6, 7], [1, 3, 4, 5, 6, 7]) == True | |
assert find_seq([1, 3, 4], [1, 3, 4]) == True | |
assert find_seq([1, 3, 4], [1, 3, 4, 5]) == True | |
assert find_seq([1, 3, 4], [0, 1, 3, 4]) == True | |
assert find_seq([1, 3, 4], [5, 1, 3, 4, 6]) == True | |
assert find_seq([1, 2, 3, 4], [1, 2, 3, 5, 1, 2, 3, 6, 1, 2, 3, 7, 1, 2, 3, 4]) == True | |
assert find_seq([1, 3, 4], []) == False | |
assert find_seq([1, 3, 4], [1, 3]) == False | |
assert find_seq([1, 3, 4], [1, 3, 5]) == False | |
assert find_seq([1, 3, 4], [5, 1, 3, 6, 4]) == False |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment