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Practice
Contest

DIFFICULTY

EASY

EXPLANATION

Several approaches exist to this problem. The simplest solution is to simply count the number of guests present at the hotel for each time from 0 to 1000, and print the maximum. A guest is present if the current time is greater than or equal to their arrival time but less than their departure time.

For a better approach, call arrivals and departures "events". Sort the 2*N events by the time at which they occur. In case of ties, place departures before arrivals. Then process the events in order, adding 1 to a count whenever an arrival occurs, and subrtacting 1 when a departure occurs, and print the maximum count.

SETTER'S SOLUTION

Can be found here.

TESTER'S SOLUTION

Can be found here.