Recognize a key-value query
Updated
A key-value query names a key and wants the payload: count, index, group, weight, last-seen time. If you can say the thing stored for x, you want a map.
What to focus on
If you can only say is x here, that is a set. If you say the item at position i, that is a list. Draw the pairs before coding.
Worked examples
count
a = [4, 1, 9, 1], how many 1s- key 1, value 2
Result: map
membership
a = [4, 1, 9, 1], is 8 present- no payload
Result: set
position
a = [4, 1, 9], item at index 1- index is already the key
Result: list, a[1]=1
Try it
Write chooseStructure(a, question). a is an array of integers. question is what you need. Return "map" when you need a payload stored for x, "set" for in-or-out, "list" for item at index i. a = [4, 1, 9, 1], how many 1s → map. a = [4, 1, 9, 1], is 8 present → set. a = [4, 1, 9], item at index 1 → list, a[1]=1.
a is a non-empty list of integers.