Algorithm/DS Problem#10: Implement a Logger

interface Logger { 
	/**
	* When a process starts, it calls 'start' with processId and startTime.
	*/
	void start(String processId, long startTime);
	
	/**
	* When the same process ends, it calls 'end' with processId and endTime.
	*/
	void end(String processId, long endTime);

	/**
	* Prints the logs of this system sorted by the start time of processes in the below format
	* {processId} started at {startTime} and ended at {endTime}
	*/
	void print();
}

We create a hashmap to store the start time of a pid. When we call end, we get the start time of the pid from the hashmap and append it into the heap.

Start: O(1)
End: O(logN)
Print: O(K)

Where k is the number of finished processes.