list1.py

# List-1
##############################

# Given an array of ints, return True if 6 appears as either the first or last element in the
# array. The array will be length 1 or more.
def first_last6(nums):
    return nums[0] == 6 or nums[-1] == 6

# Given an array of ints, return True if the array is length 1 or more, and the first element
# and the last element are equal.
def same_first_last(nums):
    return len(nums) >= 1 and nums[0] == nums[-1]

# Return an int array length 3 containing the first 3 digits of pi, {3, 1, 4}.
def make_pi():
    return [3, 1, 4]

# Given 2 arrays of ints, a and b, return True if they have the same first element or they
# have the same last element. Both arrays will be length 1 or more.
def common_end(a, b):
    return a[0] == b[0] or a[-1] == b[-1]

# Given an array of ints length 3, return the sum of all the elements.
def sum3(nums):
    return sum(i for i in nums)

# Given an array of ints length 3, return an array with the elements "rotated left" so {1, 2,
# 3} yields {2, 3, 1}.
def rotate_left3(nums):
    return [nums[1], nums[2], nums[0]]

# Given an array of ints length 3, return a new array with the elements in reverse order, so
# {1, 2, 3} becomes {3, 2, 1}.
def reverse3(nums):
    return [nums[2], nums[1], nums[0]]

# Given an array of ints length 3, figure out which is larger, the first or last element in the
# array, and set all the other elements to be that value. Return the changed array.
def max_end3(nums):
    return [max(nums[0], nums[2])] * 3

# Given an array of ints, return the sum of the first 2 elements in the array. If the array
# length is less than 2, just sum up the elements that exist, returning 0 if the array is length
# 0.
def sum2(nums):
    return sum(nums[:2])

# Given 2 int arrays, a and b, each length 3, return a new array length 2 containing their
# middle elements.
def middle_way(a, b):
    return [a[1], b[1]]

# Given an array of ints, return a new array length 2 containing the first and last elements
# from the original array. The original array will be length 1 or more.
def make_ends(nums):
    return [nums[0], nums[-1]]

# Given an int array length 2, return True if it contains a 2 or a 3.
def has23(nums):
    return 2 in nums or 3 in nums