Ruby Programming Exercise

exercise1.rb

unsorted_list = [5, 8, 1, 2, 4, 9, 7, 6, 3]
sorted_list1 = [2, 3, 5, 7, 11, 13, 17, 19]
sorted_list2 = [2, 4, 8, 10, 12, 14, 16, 18]

def min(list)
    # Google for 'ruby ternary operator'
    return list.reduce { |x, y| x < y ? x : y }
end

def max(list)
    # Fill out here
end

def sum(list)
    # Fill out here
end

def filter(list, f)
    return list.find_all { |x| f.call(x) }
end

def sumif(list, f)
    # Fill out here
end

# You may assume list1 and list2 have the same number of elements
def merge(list1, list2)
    # Fill out here
end

# This should print '1'
puts min(unsorted_list)

# This should print '9'
puts max(unsorted_list)

# This should print '45'
puts sum(unsorted_list)

# This should print '77'
puts sum(sorted_list1)

# This should print '84'
puts sum(sorted_list2)

# This should print out '[11, 13, 17, 19, 23]'
puts filter(sorted_list1, lambda { |x| x > 10 }).inspect()

# This should print out '[12, 14, 16, 18]'
puts filter(sorted_list2, lambda { |x| x > 10 }).inspect()

# This should print '17'
puts sumif(sorted_list1, lambda { |x| x < 10 }).inspect()

# This should print '25'
puts sumif(unsorted_list, lambda { |x| x % 2 == 1 }).inspect()

# This should print out '[2, 2, 3, 4, 5, 8, 7, 10, 11, 12, 13, 14, 16, 17, 18, 19]'
puts merge(sorted_list1, sorted_list2).inspect()

Expected output:

$ ruby exercise.rb 
1
9
45
77
84
[11, 13, 17, 19]
[12, 14, 16, 18]
17
25
[2, 2, 3, 4, 5, 8, 7, 10, 11, 12, 13, 14, 16, 17, 18, 19]