- Install Node.js
- Fork this repository: https://github.com/AlreadyBored/basic-js
- Clone your newly created repo: https://github.com/<%your_github_username%>/basic-js/
- Go to folder
basic-js
- To install all dependencies use
npm install
- Run
npm run test
in command line. - You will see the number of pending, passing and failing tests. 100% of passing tests is equal to max score for the task
- If you catch error like this you can try to make
npm install -g node-gyp
Submit to rs app
- Open rs app and login
- Go to submit task page
- Select your task (BasicJS)
- Press the submit button and enjoy
- We recommend you to use Node.js of version 16.x.x LTS. If you use any of features, that does not supported by Node.js v16, there may be problems with task submit.
- Please, be sure that each of your tests is limited to 30 sec.
Your task is to write several functions that are the solution to the subtasks. Subtasks descriptions, as well as instructions on how to run tests and submit solutions are below.
Your task is to count the cats hidden in the backyard (presented by two-dimensional Array
). Cats hide well, but their ears ("^^"
) are clearly visible. Your task is to implement the countCats(backyard)
function that will count cats. Good luck!
Number of cats found should be number
. If no cats found, function should return 0
.
For example:
countCats([ [0, 1, '^^'], [0, '^^', 2], ['^^', 1, 2] ])
=> 3
Write your code in src/count-cats.js
.
To determine the age of archaeological finds, radioisotope dating is widely used. One of its types is radiocarbon dating.
The approximate age of the sample is calculated by measuring the ratio of the modern activity of the C14 isotope to the activity of the same isotope in the sample.
About calculations
You can use the formula from the article at the link above. 0.693 is an approximation of the natural logarithm of two.Your task is to implement the function dateSample(sampleActivity)
that calculates sample approximate age (in years). Please use given MODERN_ACTIVITY
and HALF_LIFE_PERIOD
.
Function parameter sampleActivity
is a string
. Calculated sample age must be number
.
Age must be integer. Age must be rounded up (ceiling). In case of wrong input parameter type or inadequate activity value or absence of argument function must return false
.
For example:
dateSample('1')
=> 22387
(or 22392
depending on formula used)
dateSample('WOOT!')
=> false
Write your code in src/carbon-dating.js
.
Imagine you and your friends decide to create a dream team. This team should have a cool secret name that contains encrypted information about it. For example, these may be the first letters of the names of its members in upper case sorted alphabetically.
Your task is to implement the createDreamTeam(members)
function that returns name of a newly made team (string
) based on the names of its members (Array
). Good luck!
Names of the members should be strings
. Values with other type should be ignored. In case of wrong members
type function must return false
.
NB! Team member name may contain whitespaces.
For example:
createDreamTeam(['Matt', 'Ann', 'Dmitry', 'Max'])
=> 'ADMM'
createDreamTeam(['Olivia', 1111, 'Lily', 'Oscar', true, null])
=> 'LOO'
Write your code in src/dream-team.js
.
Your task is to implement the function getSeason(date)
that accepts Date
object and returns the time of the year that matches it.
Time of the year must be string
.
Seasons in English
The names of the seasons in English are: spring, summer, autumn (fall), winter.If the date
argument was not passed, the function must return the string
'Unable to determine the time of year!'
. If the date
argument is invalid, the function must throw an Error
with message Invalid date!
.
Shh! An enemy scout has lurked among the arguments that come into this function.
He is guided by the famous proverb: “If it looks like a duck, swims like a duck and quacks like a duck, then it probably is a duck (who cares what it really is)”. He is expertly disguised as a real date, but a clever javascript developer can catch him and throw
an Error
with message Invalid date!
just in time!
For example:
const springDate = new Date(2020, 02, 31)
getSeason(springDate)
=> 'spring'
Write your code in src/what-season.js
.
Tower of Hanoi is famous mathematical puzzle of the 18th century.
It consists of three rods and a number of disks of different sizes, which can slide onto any rod. The puzzle starts with the disks in a neat stack in ascending order of size on one rod, the smallest at the top, thus making a conical shape.
The objective of the puzzle is to move the entire stack to another rod, obeying the following simple rules:
- Only one disk can be moved at a time.
- Each move consists of taking the upper disk from one of the stacks and placing it on top of another stack or on an empty rod.
- No larger disk may be placed on top of a smaller disk.
Your task is much easier than coming up with an algorithm that solves this puzzle :)
Implement the function calculateHanoi
that accepts diskNumber
and turnsSpeed
parameters. diskNumber
is a number of disks and turnsSpeed
is the speed of moving discs (in turns per hour).
Both parameters are numbers
.
calculateHanoi
function returns an object with 2 properties:
turns
(minimumnumber
of turns to solve the puzzle)seconds
(minimumnumber
of seconds to solve the puzzle at a giventurnsSpeed
, seconds must be an integer, obtained from rounded down (floor) calculation result)
You don't need to validate parameters.
For example:
calculateHanoi(9, 4308)
=> { turns: 511, seconds: 427 }
Write your code in src/hanoi-tower.js
.
Your task is to implement the function transform(arr)
that takes an array
and returns transformed array, based on the control sequences that arr
contains.
Control sequences are defined string
elements of the mentioned array
:
--discard-next
excludes the next element of the array from the transformed array.--discard-prev
excludes the previous element of the array from the transformed array.--double-next
duplicates the next element of the array in the transformed array.--double-prev
duplicates the previous element of the array in the transformed array.
For example:
transform([1, 2, 3, '--double-next', 4, 5])
=> [1, 2, 3, 4, 4, 5]
transform([1, 2, 3, '--discard-prev', 4, 5])
=> [1, 2, 4, 5]
The function must not affect inital array. Control sequences are applied from left to right to initial array elements. Control sequences do not fall into the transformed array. Control sequences in initial array don't occur in a row. If there is no element next to the control sequence to which it can be applied in the initial array, or this element was previously deleted, it does nothing. The function should throw an Error
with message 'arr' parameter must be an instance of the Array!
if the arr
is not an Array
.
Write your code in src/transform-array.js
.
Let's practice in chaining!
Your task is to create the object chainMaker
that creates chains. The finished chain is a string
and looks like this: '( value1 )~~( value2 )~~( value3 )'
.
The chainMaker
has several methods for creating chains and modifying them:
getLength
returns the current chain length as a number;addLink(value)
adds a link containing astring
representation of thevalue
to the chain;removeLink(position)
removes a chain link in the specified position;reverseChain
reverses the chain;finishChain
ends the chain andreturns
it.
addLink
, reverseChain
and removeLink
methods are chainable, while the another ones are not. If addLink
is called with no arguments, it adds an empty link ('( )'
) to the chain. If removeLink
accepts invalid position
(e.g. not a number, or a fractional number, or corresponding to a nonexistent link), it must throw an Error
with message You can't remove incorrect link!
. After calling the finishChain
method, the existing chain must be deleted, as if an Error
was thrown.
For example:
chainMaker.addLink(1).addLink(2).addLink(3).finishChain()
=> '( 1 )~~( 2 )~~( 3 )'
chainMaker.addLink(1).addLink(2).removeLink(1).addLink(3).finishChain()
=> '( 2 )~~( 3 )'
chainMaker.addLink(1).addLink(2).reverseChain().addLink(3).finishChain()
=> '( 2 )~~( 1 )~~( 3 )'
Write your code in src/simple-chain.js
.
Your task is to implement the class DepthCalculator
with method calculateDepth
that takes an array
and returns its depth.
calculateDepth
method must pass the given array recursively. Depth of a flat array is 1. Method must correctly work with arrays
that contain no elements or contain empty arrays
.
For example:
const depthCalc = new DepthCalculator();
depthCalc.calculateDepth([1, 2, 3, 4, 5])
=> 1
depthCalc.calculateDepth([1, 2, 3, [4, 5]])
=> 2
depthCalc.calculateDepth([[[]]])
=> 3
Write your code in src/recursive-depth.js
.
Your task is to implement the function repeater(str, options)
.
This function returns a repeating string
based on the given parameters:
str
is astring
to repeat;options
is anobject
of options, that contains properties:repeatTimes
sets thenumber
of repetitions of thestr
;separator
is astring
separating repetitions of thestr
;addition
is an additionalstring
that will be added to each repetition of thestr
;additionRepeatTimes
sets thenumber
of repetitions of theaddition
;additionSeparator
is astring
separating repetitions of theaddition
.
The str
and addition
parameters are strings
by default. In case when type of these parameters is different, they must be converted to a string
.
separator
and additionSeparator
parameters are strings
.
repeatTimes
and additionRepeatTimes
are integer numbers
(in the absence of any of them, the corresponding string is not repeated).
The only indispensable parameter is str
, any others may be not defined. separator
default value is '+'
. additionSeparator
default value is '|'
.
For example: repeater('STRING', { repeatTimes: 3, separator: '**', addition: 'PLUS', additionRepeatTimes: 3, additionSeparator: '00' })
=> 'STRINGPLUS00PLUS00PLUS**STRINGPLUS00PLUS00PLUS**STRINGPLUS00PLUS00PLUS'
Write your code in src/extended-repeater.js
.
Cryptography is awesome! Let's try to organize production of encryption machines. Our machines will use one of the encryption methods that are easy to understand, but also not amenable to simple cryptanalysis - the Vigenere cipher.
Our machine will have 2 modifications: direct and reverse (the type of machine is determined at the moment of creation). The direct machine simply encodes and decodes the string that was transmitted to it, and the reverse machine returns an inverted string after encoding and decoding.
Your task is to implement the class VigenereCipheringMachine
. constructor
of this class
accepts true
(or nothing) to create direct machine and false
to create reverse machine.
Each instance of VigenereCipheringMachine
must have 2 methods: encrypt
and decrypt
.
encrypt
method accepts 2 parameters: message
(string
to encode) and key
(string
-keyword).
decrypt
method accepts 2 parameters: encryptedMessage
(string
to decode) and key
(string
-keyword).
These parameters for both methods are mandatory. If at least one of them has not been given, an Error
with message Incorrect arguments!
must be thrown. The text returned by these methods must be uppercase. Machines encrypt and decrypt only latin alphabet (all other symbols remain unchanged).
You don't need to validate value sent to constructor
and to encrypt
and decrypt
methods (except throwing an Error
on absence of argument for these methods).
For example:
const directMachine = new VigenereCipheringMachine();
const reverseMachine = new VigenereCipheringMachine(false);
directMachine.encrypt('attack at dawn!', 'alphonse')
=> 'AEIHQX SX DLLU!'
directMachine.decrypt('AEIHQX SX DLLU!', 'alphonse')
=> 'ATTACK AT DAWN!'
reverseMachine.encrypt('attack at dawn!', 'alphonse')
=> '!ULLD XS XQHIEA'
reverseMachine.decrypt('AEIHQX SX DLLU!', 'alphonse')
=> '!NWAD TA KCATTA'
Write your code in src/vigenere-cipher.js
.
Your task is to implement function that accepts two strings (s1
and s2
) and returns number of common characters between them.
For example:
getCommonCharacterCount('aabcc', 'adcaa')
=> 3
Write your code in src/common-character-count.js
.
Your task is to implement function that accepts integer number (n
) and returns maximal number you can obtain by deleting exactly one digit of the given number.
For example:
deleteDigit(152) => 52
Write your code in src/delete-digit.js
.
Your task is to implement function that accepts an array of domains (domains
) and returns the object with the appearances of the DNS.
For example:
getDNSStats(['code.yandex.ru', 'music.yandex.ru', 'yandex.ru'])
=> {'.ru': 3, '.ru.yandex': 3, '.ru.yandex.code': 1,'.ru.yandex.music': 1}
Write your code in src/dns-stats.js
.
Your task is to implement function that accepts string (str
) and returns its encoded version.
For example:
encodeLine('aabbbc')
=> '2a3bc'
Write your code in src/encode-line.js
.
There's a list of file, since two files cannot have equal names, the one which comes later will have a suffix (k), where k is the smallest integer such that the found name is not used yet.
Your task is to implement function that accepts array of names (names
) and returns an array of names that will be given to the files.
For example:
renameFiles(["file", "file", "image", "file(1)", "file"])
=> ["file", "file(1)", "image", "file(1)(1)", "file(2)"]
Write your code in src/file-names.js
.
Your task is to implement function that accepts email address (email
) and returns it's domain.
For example:
getEmailDomain('prettyandsimple@example.com')
=> 'example.com'
Write your code in src/get-email-domain.js
.
The MAC-48 address is six groups of two hexadecimal digits (0 to 9 or A to F) separated by hyphens.
Your task is to implement function that accepts string (inputString
) and returns true
if string is valid MAC-48 address.
For example:
isMAC48Address('00-1B-63-84-45-E6')
=> true
Write your code in src/mac-adress.js
.
Given matrix, a rectangular matrix of integers, just add up all the values that don't appear below a "0".
For example:
const matrix = [
[0, 1, 1, 2],
[0, 5, 0, 0],
[2, 0, 3, 3]
];
getMatrixElementsSum(matrix) => 9
Write your code in src/matrix-elements-sum.js
.
In the popular Minesweeper game you have a board with some mines and cells that have a number in it that indicates the total number of mines in the neighboring cells. Starting off with some arrangement of mines we want to create a Minesweeper game setup.
For example:
const matrix = [
[true, false, false],
[false, true, false],
[false, false, false]
];
minesweeper(matrix) => [
[1, 2, 1],
[2, 1, 1],
[1, 1, 1]
];
Write your code in src/mine-sweeper.js
.
Given an array with heights, sort them except if the value is -1
.
Your task is to implement function that accepts array (arr
) and returns it sorted
For example:
sortByHeight([-1, 150, 190, 170, -1, -1, 160, 180])
=> [-1, 150, 160, 170, -1, -1, 180, 190]
Write your code in src/sort-by-height.js
.
Your task is to implement function that accepts a number (n
) and returns the sum of its digits until we get to a one digit number.
For example:
For 100, the result should be 1 (1 + 0 + 0 = 1)
getSumOfDigits(100)
=> 1
For 91, the result should be 1 (9 + 1 = 10, 1 + 0 = 1)
getSumOfDigits(91)
=> 1
Write your code in src/sum-digits.js
.
& tasks:
- Common character count
- Delete digit
- DNS stat
- Encode line
- File names
- Get email domain
- Is MAC-48 Adress?
- Matrix elements sum
- Minesweeper
- Sort by height
- Sum digits
are integrated from Short track 2021 repo
& Thanks mikhama for assistance!