Given a log of user with clicks, find user with maximum number of clicks in a given interval

A list is given with process_id, user_id, clicks, starttime,end time.
For e.g:
[
[ 1, "a" ,100,3.00,4.00]
[ 2, "b" ,120,3.30,4.30]
[ 3, "a" ,50,3.45,4.15]
[ 4, "b" ,70,4.15,5.00]
[ 5, "c" ,90,4.30,5.00]
]

the answer is
Interval -( 3.00 - 4.00)
Output: a
since a uses 100 + 50