Given an array of integers representing patient check-in times, write an efficient algorithm to find the peak operational hours for a clinic.
Treat each integer as an hour. Return all hours that occur most frequently, sorted in ascending order. The input contains at least one hour, and duplicate hours represent multiple check-ins.
Function: def peak_operational_hours(check_in_times):
Input is a list of integers. Output is a list of integers containing every hour tied for the maximum frequency.
def peak_operational_hours(check_in_times):