Different repeats

Implement a class TrackRepeat with the following methods:

• add(x, k): add the number x to the list k times
• check(): return True if each number on the list has a different number of occurrences, and otherwise False

The time complexity of both methods should be $O(1)$.

For example, the list $[1,3,1,1,2,3,1]$ contains three distinct numbers $1$, $2$ and $3$. The number $1$ occurs $4$ times, the number $2$ occurs $1$ times, and the number $3$ occurs $2$ times. Thus each number has a different number of occurrences ($4$, $1$ and $2$ occurrences).

In a file trackrepeat.py, implement a class TrackRepeat according to the following template:

class TrackRepeat:
    def __init__(self):
        # TODO

    def add(self, x, k):
        # TODO

    def check(self):
        # TODO

if __name__ == "__main__":
    t = TrackRepeat()
    print(t.check()) # True
    t.add(1, 3)
    print(t.check()) # True
    t.add(2, 3)
    print(t.check()) # False
    t.add(2, 2)
    print(t.check()) # True
    t.add(3, 1)
    print(t.check()) # True
    t.add(3, 4)
    print(t.check()) # False