codewars/courses/python_for_begginers/list.py

from math import factorial

def list_1():
    cnt = 0
    my_dict = {}
    my_list = list(map(int, input().split()))
    for i in my_list:
        if i not in my_dict.keys():
            my_dict.update({i:1})
        else:
            my_dict.update({i: my_dict.get(i) + 1})
    for i in my_dict.values():
        if i >= 3:
            cnt += int(factorial(i)/(2*factorial(i - 2)))
        elif i == 2:
            cnt += 1

    print(my_list)
    print(my_dict)
    print("counter:", cnt)

list_1()