Exclusive Time of Functions

Statement

We are given an integer number, n, representing the number of functions running in a single-threaded CPU, and an execution log, which is essentially a list of strings. Each string has the format {function id}:{"start" | "end"}:{timestamp}, indicating that the function with function id either started or stopped execution at the time identified by the timestamp value. Each function has a unique ID between $0$ and $n-1$. Compute the exclusive time of the functions in the program.

Note: The exclusive time is the sum of the execution times for all the calls ...