Zeros

Task

Implement function zeros(str), that for given expression will return the number of zeros in the end of number. Expression contains only factorials of numbers and multiplying signs, like: zeros('5!*7!*6!!*7!!') 5! === 1 * 2 * 3 * 4 * 5 10!! === 2 * 4 * 6 * 8 * 10 7!! === 1 * 3 * 5 * 7

zeros('5!') // -> 1 because 5! === 120
zeros('10!') // -> 2 because 10! === 3628800
zeros('9!!*10!!') // 2 -> because 9!!*10!! === 3628800
8!! = 2 * 4 * 6 * 8 = 384
9!! = 1 * 3 * 5 * 7 * 9 = 945
10!! = 2 * 4 * 6 * 8 * 10 = 3840
8!! * 9!! * 10!! = 1 393 459 200‬

11!! = 1 * 3 * 5 * 7 * 9 * 11 = 10 395
9!! * 10!! * 11!! = 37 721 376 000‬

20!! = 3 715 891 200‬
9!! * 10!! * 20!! = 13 484 225 986 560 000‬ 

7!! = 105
9!! = 945
7!! * 9!! = ...225

Write your code in src/index.js

Prepare and test

1. Install Node.js
2. Fork this repository: https://github.com/Shastel/zeros/
3. Clone your newly created repo: https://github.com/<%your_github_username%>/zeros/
4. Go to folder zeros
5. To install all dependencies use npm install
6. Run npm test in command line
7. You will see the number of passing and failing tests you 100% of passing tests is equal to 100p in score

Submit to rs app

1. Open rs app and login
2. Go to submit task page
3. Select your task (zeros)
4. Press the submit button and enjoy

credits @yankouskia