CS计算机代考程序代写 # First let’s do some general

# First let’s do some general
# code block practice

# Given a hash, return
# all values that are divisble
# by 2. Assume values are ints
# Use a code block.
def evens_string(hash)
raise “unimplemented”
end

# Now let’s up the stakes
# Given an array of elements
# return a new array whose
# elements have been processed
# by the code block

# If no code block is given,
# simply return an array where
# every element is increased by 1
def map_w_code_block(arr)
raise “unimplemented”
end

# Time for some regex practice!
# Write a regular expression to
# capture a time.

# Times are defined in the following
# way:
# A 2 digit hour (from 01 to 12)
# A 2 digit minute (from 00 to 59)
# A 2 digit second (from 00 to 59)
# A two letter indication : A.M., P.M.
# EX. 12:31:59 P.M.

# If I give you a valid time:
# return the string “It is _ _”,
# where the first blank is replaced
# by the hour, and the second blank
# is replaced by A.M. or P.M.
# EX. “It is 12 P.M.” (It doesn’t
# matter if it’s 12:59:59 – It’s still
# 12 for us)
# If I give you ANYTHING else
# return the string “Invalid”
def time_teller(time_str)
raise “unimplemented”
end

# Alright, we’ve got three basic
# exercises out of the way, let’s
# put it all together!

class Grader

# You’ll be given a file of strings
# Each line has a first name and last name
# (Start with capital, then lowercase),
# followed by a comma and then their grade
# a number from 0 to 100
# EX. “Frodo Baggins, 98”
def initialize(filename)
# initialize some relevant data
# structure here
File.foreach(filename) do |line|
# code here
end
end

# Because 330 is so great,
# we’ll sometimes spontaneously
# give all students some extra
# credit, defined by a code block
# we pass in. Update your data
# to add this extra credit
def add_extra_credit()
raise “unimplemented”
end

# Return the grade for the
# specified student
def get_grades_for_student(student_Name)
raise “unimplemented”
end
end