I gave phone screen few weeks ago. i solved the below problem by finidng number of components of graph, in order to get the number of separate infections originated outside the warehouse(as per my conversation with interviewer) But i never understood the question since no inpot/output were provided. I think this should be combination of connected components in a directed graph and topological sort of each component to find the root (first infected employees) in each component. I didn't clear the interview due to communication issue with interviewer, i was not able to get proper input/output format as the interviewr is tyring to get input/output also defined by me.

Problem Statement:

*At the beginning of COVID outbreak, Amazon warehouse had a burst number of employees who have been diagnosed with the Covid virus.

Their supervisors tracks down on who they have been contacted with and mark all people they have been contacted with and who are also infected by the covid virus.

Once an employee hass been confirmed with the inection , they are required to stay quarantined until they are tested negative.

we now need to understand the breakout pattern and report the potential first employees who were infected to better control the virus.
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