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#
# Queue.py
# Simulate a queue where people arrive randomly with an average time of
# X seconds between people and are dealt with in Y seconds on average
# Use a loop with a 1 second step in the simulation
#
# Print the maximum wait that any one of 1000 simulated people had
# Note this solution uses numpy to generate distrubibutions, you can
# also "math" functions and "random" functions (import math,random)
#
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X = 10 # starting value, can be adjusted
Y = 7  # starting value, can be adjusted
nPerson = 1000 # number of people to simulate, stop when all dealt with

import numpy as np

def timeToNext(beta):
    """Return time to next person, input is beta = 1/(average arrival rate)"""
    # functional form of time to next person if ac is the average arrival time
    # is p(t) = 1/beta * exp(- t / beta )
    # where beta = beta
    # np.random.exponential uses scale = beta
    # https://docs.scipy.org/doc/numpy-1.13.0/reference/generated/numpy.random.exponential.html
    ranExp = np.random.exponential(scale = beta, size=1)
    return int(ranExp) # note forcing integer times here to simplify

def addAPerson(t,q):
    """ Function to add a person to the queue with average time between people = X"""
    # t = time added
    # q = your queue
    pass # write your function here

def removeAPerson(t,q):
    """Function to remove a person how has been dealt with, return time they waited"""
    # t = time removed
    # q = your queue
    return 0 #your function here, return time waited

def arriveTimesArray(n,dt):
    """Return a numpy array of integers, which are the times each person will arrive"""    
    return 0 # return the array here

def timerLoop(X,Y):
    """Run a loop to add and remove people as required"""
    arriveTimes = arriveTimesArray(nPerson,X)
    # queue
    q = []
    # waied times
    wait = []
    ## loop over the times from 0 -> ... in steps of 1s 
    ## until there are no people to arrive and noone in the queue
    ## store the time each person waited in the "wait" array as an integer
    #
    # np.max is the maximum of an array, np.mean is the average
    print("Max time waited was {}s average {}s".format(np.max(wait),np.mean(wait)))

timerLoop(X,Y)
print("\nOnce this works try rerunning with different arrival times and processing times\ntimerLoop(10,7) # default values")