Update and rename K.cpp to K.cpp - adjustments

Hello :)
I have a few advices do make concerning your code for problem K. They are as follows:
- line 75: '}' missing;
- line {70, 59}: you should print newline char after printing the final result
- lines {63, 46, 7, 6}: in my opinion, variable of type int certainly can contain a number below 10^9, so you can save mamory by not using long long int
- line 4: sum of the inversions could be very big, so I would advice to use type long long unsigned int for counting them
- line 60: you could place the 'return 0' command, so the program ends quicker
- line 40: there is no need for the 'return' statemant, because the function already ends after it
That would be all :)