---
id: 699c8e045ee7cb94ed2322dd
title: "Challenge 222: Equinox Shadows"
challengeType: 29
dashedName: challenge-222
---

# --description--

Today is the equinox, when the sun is directly above the equator and perfectly overhead at noon. Given a time, determine the shadow cast by a 4-foot vertical pole.

- The time will be a string in `"HH:MM"` 24-hour format (for example, `"15:00"` is 3pm).
- You will only be given a time in 30 minute increments.

Rules:

- The sun rises at 6am directly `"east"`, and sets at 6pm directly `"west"`.
- A shadow always points opposite the sun.
- The shadow's length (in feet) is the number of hours away from noon, cubed.
- There is no shadow before sunrise (before 6am), after sunset (6pm or later), or at noon.

Return:

- If a shadow exists, return `"(length)ft (direction)"`. For example, `"8ft west"`.
- Otherwise, return `"No shadow"`.

For example, given `"10:00"`, return `"8ft west"` because 10am is 2 hours from noon, so 2<sup>3</sup> = 8 feet, and the shadow points west because the sun is in the east at 10am.

# --hints--

`get_shadow("10:00")` should return `"8ft west"`.

```js
({test: () => { runPython(`
from unittest import TestCase
TestCase().assertEqual(get_shadow("10:00"), "8ft west")`)
}})
```

`get_shadow("15:00")` should return `"27ft east"`.

```js
({test: () => { runPython(`
from unittest import TestCase
TestCase().assertEqual(get_shadow("15:00"), "27ft east")`)
}})
```

`get_shadow("12:00")` should return `"No shadow"`.

```js
({test: () => { runPython(`
from unittest import TestCase
TestCase().assertEqual(get_shadow("12:00"), "No shadow")`)
}})
```

`get_shadow("17:30")` should return `"166.375ft east"`.

```js
({test: () => { runPython(`
from unittest import TestCase
TestCase().assertEqual(get_shadow("17:30"), "166.375ft east")`)
}})
```

`get_shadow("05:00")` should return `"No shadow"`.

```js
({test: () => { runPython(`
from unittest import TestCase
TestCase().assertEqual(get_shadow("05:00"), "No shadow")`)
}})
```

`get_shadow("06:00")` should return `"216ft west"`.

```js
({test: () => { runPython(`
from unittest import TestCase
TestCase().assertEqual(get_shadow("06:00"), "216ft west")`)
}})
```

`get_shadow("18:00")` should return `"No shadow"`.

```js
({test: () => { runPython(`
from unittest import TestCase
TestCase().assertEqual(get_shadow("18:00"), "No shadow")`)
}})
```

`get_shadow("07:30")` should return `"91.125ft west"`.

```js
({test: () => { runPython(`
from unittest import TestCase
TestCase().assertEqual(get_shadow("07:30"), "91.125ft west")`)
}})
```

`get_shadow("00:00")` should return `"No shadow"`.

```js
({test: () => { runPython(`
from unittest import TestCase
TestCase().assertEqual(get_shadow("00:00"), "No shadow")`)
}})
```

# --seed--

## --seed-contents--

```py
def get_shadow(time):

    return time
```

# --solutions--

```py
def get_shadow(time):
    hour_str, minute_str = time.split(":")
    hours = int(hour_str)
    minutes = int(minute_str)
    time_in_hours = hours + minutes / 60

    if time_in_hours < 6 or time_in_hours >= 18 or time_in_hours == 12:
        return "No shadow"

    hours_from_noon = abs(12 - time_in_hours)
    length = hours_from_noon ** 3
    direction = "west" if time_in_hours < 12 else "east"

    return f"{length:g}ft {direction}"
```