def string_times(str, n): """ Given a string and a non-negative int n, return a larger string that is n copies of the original string. """ return str*n def front_times(str, n): """ Given a string and a non-negative int n, we'll say that the front of the string is the first 3 chars, or whatever is there if the string is less than length 3. Return n copies of the front. """ return str[:(3 if len(str)>3 else len(str))]*n def string_bits(str): """ Given a string, return a new string made of every other char starting with the first, so "Hello" yields "Hlo". """ return str[::2] def string_splosion(str): """ Given a non-empty string like "Code" return a string like "CCoCodCode". """ result = "" for i in range(1,len(str)+1): result = result + str[:i] return result def last2(str): """ Given a string, return the count of the number of times that a substring length 2 appears in the string and also as the last 2 chars of the string, so "hixxxhi" yields 1 (we won't count the end substring). """ count = 0 for i in range(0, len(str)-2): if str[i:i+2] == str[-2:]: count += 1 return count def array_count9(nums): """Given an array of ints, return the number of 9's in the array.""" return nums.count(9) def array_front9(nums): """ Given an array of ints, return True if one of the first 4 elements in the array is a 9. The array length may be less than 4. """ return nums[:4].count(9) > 0 def array123(nums): """Given an array of ints, return True if .. 1, 2, 3, .. appears in the array somewhere. """ for i in range(0,len(nums)-2): if [1,2,3] == nums[i:i+3]: return True return False def string_match(a, b): def splitter(str,n): result = [] for i in range(0,len(str)-n+1): result.append(str[i:i+n]) return result count = 0 b_splitted = splitter(b,2) for pair in splitter(a,2): if pair in splitter(b,2): count += 1 return count def string_match(a, b): """ Given 2 strings, a and b, return the number of the positions where they contain the same length 2 substring. So "xxcaazz" and "xxbaaz" yields 3, since the "xx", "aa", and "az" substrings appear in the same place in both strings. """ def splitter(str,n): """Helper that returns every n-length substring""" result = [] for i in range(0,len(str)-n+1): result.append(str[i:i+n]) return result count = 0 a_split = splitter(a,2) b_split = splitter(b,2) for i in range(0, len(a_split) if len(a_split)<=len(b_split) else len(b_split)): if a_split[i] == b_split[i]: count += 1 return count