Frequency by Level of Nesting

Create a function that takes in a nested list and an element and returns the frequency of that element by nested level.

Examples

freq_count([1, 4, 4, [1, 1, [1, 2, 1, 1]]], 1)
➞ [[0, 1], [1, 2], [2, 3]]
# The list has one 1 at level 0, 2 1's at level 1, and 3 1's at level 2.

freq_count([1, 5, 5, [5, [1, 2, 1, 1], 5, 5], 5, [5]], 5)
➞ [[0, 3], [1, 4], [2, 0]]

freq_count([1, [2], 1, [[2]], 1, [[[2]]], 1, [[[[2]]]]], 2)
➞ [[0, 0], [1, 1], [2, 1], [3, 1], [4, 1]]

Notes

• Start the default nesting (a list with no nesting) at 0.
• Output the nested levels in order (e.g. 0 first, then 1, then 2, etc).
• Output 0 for the frequency if that particular level has no instances of that element (see example #2).