Anagrams and consecutive runs

Questions 1 to 5 of 8

1. 1. Why can't a Python list of 26 letter counts be used directly as a dict key for grouping anagrams?

   Lists are too slow to hash, so the dict would take longer than sorting the wordsA list can be changed, so Python does not allow it as a dict keyA dict only accepts string keys, so any other type raises KeyError as soon as it is usedA list holds only 26 slots, so it cannot store the six words in the example
2. 2. In the longest-consecutive code, why does if n - 1 in numbers decide to continue and skip n?

   It sorts the values, so the walk can use a binary searchIt checks for negative numbers, which the walk cannot handleIt starts a count only at the first value of each run, so each run is walked onceIt removes duplicate values, so the set never holds a repeat
3. 3. Which statements about the two keys for grouping anagrams are true? Pick all that apply.

   Pick every answer that is true.

   The sorted-letter key and the letter-count key put the same words in the same groupsThe sorted-letter key for 'listen' is 'eilnst'The letter-count key for 'eat' is a string of 26 charactersA plain dict keeps the groups in the order their first word appeared
4. 4. Which statements about a set in the consecutive-run code are true? Pick all that apply.

   Pick every answer that is true.

   {1, 2, 2} creates a set with the two values 1 and 2Adding the same value twice to a set stores it only onceRemoving items from a set inside a for loop over that same set raises RuntimeErrorA list checks in as fast as a set does
5. 5. What does this program print? ``python from collections import defaultdict words = ['tab', 'bat', 'cat', 'act'] groups = defaultdict(list) for w in words: groups[''.join(sorted(w))].append(w) print(dict(groups)) ``

   {'abt': ['tab', 'bat', 'cat', 'act']}{'tab': ['tab', 'bat'], 'cat': ['cat', 'act']}{'act': ['cat', 'act'], 'abt': ['tab', 'bat']}{'abt': ['tab', 'bat'], 'act': ['cat', 'act']}