First clear solution for Changing direction by mortonfox - python coding challenges

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First solution in Clear category for Changing direction by mortonfox

def changing_direction(elements: list) -> int:
    dir = count = 0
    for a, b in zip(elements, elements[1:]):
        dir2 = a - b
        if dir2:
            if dir2 * dir < 0: count += 1
            dir = dir2
    return count

print("Example:")
print(changing_direction([1, 2, 3, 4, 5]))

assert changing_direction([1, 2, 3, 4, 5]) == 0
assert changing_direction([1, 2, 3, 2, 1]) == 1
assert changing_direction([1, 2, 2, 1, 2, 2]) == 2

print("The mission is done! Click 'Check Solution' to earn rewards!")

Sept. 9, 2022

Comments:

nikolaypasevich on Dec. 17, 2022, 4:06 a.m.
not puzzled, readable and clear code. Nice

nikolaypasevich on Dec. 17, 2022, 4:09 a.m.
I've solved it this task without 'if', but your solutions more readable for myself )))

Arapi on April 14, 2023, 10:35 a.m.
Really nice and clear and easy to understand.

freeman_lex on April 10, 2024, 6:48 p.m.
This Python function `changing_direction` takes a list of elements as input and returns the count of times the direction changes between consecutive elements in the list. Let's break down the code step by step: <ol> <li>`def changingdirection(elements: list) -> int:`: This line defines a function named `changingdirection` that takes a single argument `elements`, which is expected to be a list. The function is annotated to return an integer (`-> int`), indicating that it returns an integer value.</li> <li>`dir = count = 0`: This line initializes two variables, `dir` and `count`, both set to 0. <ul> <li>`dir` is used to track the direction between consecutive elements.</li> <li>`count` is used to count the number of direction changes.</li> </ul></li> <li>`for a, b in zip(elements, elements[1:]):`: This line iterates through pairs of consecutive elements in the list. It uses the `zip` function to create pairs of elements. `elements[1:]` creates a new list containing all elements except the first one, effectively shifting the list by one element. By iterating through pairs of elements using `zip`, the loop effectively iterates through consecutive pairs of elements in the original list.</li> <li>`dir2 = a - b`: This line calculates the difference between the current element `a` and the next element `b`, storing it in the variable `dir2`. This difference represents the change in direction between the two elements.</li> <li>`if dir2:`: This line checks if `dir2` is not equal to 0, meaning there is a change in direction.</li> <li>`if dir2 * dir < 0: count += 1`: This line checks whether the current direction (`dir2`) has a different sign than the previous direction (`dir`). If it does, it means there's a change in direction, and the `count` variable is incremented by 1. <ul> <li>`dir` keeps track of the previous direction. It is initially set to 0 and updated to `dir2` after each iteration.</li> </ul></li> <li>`dir = dir2`: This line updates the `dir` variable to store the current direction for the next iteration.</li> <li>`return count`: Finally, the function returns the total count of direction changes observed in the list.</li> </ol> In summary, this function calculates the number of times the direction changes between consecutive elements in the input list and returns that count.

List but not the least

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