Forem: Alex Wawl 🐼

[Devmates.co] 📣 Expressive Words

Alex Wawl 🐼 — Wed, 25 Dec 2019 13:08:54 +0000

Hello👋,
My name is Alex and I'm maker of Devmates.co. 😊

We are resolving daily coding problems which asked by top tech companies together. We share our solutions, give some help if anyone stuck, support each other and just hangout together in the internet. 🍻☕️💬

I get this problem from our members or just searching them in the internet(leetcode forums, Glassdoor, teamblind, etc.). Sometimes this problem can be very easy, sometimes too 👷‍♂️hard, everything depends on skills but we are trying to resolve all of them and Have Fun. 🙌

Today I want to share problem which was asked by 🏢Google.

Problem:

Given an original word and an expressive word.

Return the starting and ending index of repeating characters which are not present in original string.

For example, given an original word "Hello" and an expressive word "Heeeellooo". "e" is being repeated three times and "o" is being repeated two times so you have to return [["e", 2, 4], ["o", 8, 9]]

Example:

Input:
original="Hello",
expressiveWord = "Heeeellooo"
Output: [["e", 2, 4], ["o", 8, 9]]
Why: "e" is being repeated three times and
"o" is being repeated two times.

Link to the Problem

🙌 Don't hesitate to share your solutions directly on devmates.co

[Devmates.co] Jumps with Boost by 🏢Microsoft

Alex Wawl 🐼 — Mon, 16 Dec 2019 09:01:41 +0000

Hello👋,
My name is Alex and I'm maker of Devmates.co. 😊

Today I want to share problem which was asked by 🏢Microsoft.

Problem:

Given an array containing numbers 1 to n where array[i] = i+1.

Find the minimum number of jumps required from arr[0] to arr[n-1].

From current position i, we can jump to positions i+1, i+2, i+3 and I+4
There are optional boosters given in the form of an object like - {1: 15, 5: 10} which means, if we reached at index 1 we can directly jump to index 15 similarly, if we reached at index 5, we can directly jump to index 10.

Example:

Input:
arr = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15]
boosters = {3: 8, 5:10}
Output: 4
Why: (1 -> 5 -> 10 -> 14 -> 15)

Link to the Problem

🙌 Don't hesitate to share your solutions directly on devmates.co

[Devmates.co] Subtract Two Integers Represented as Array by 🏢Google

Alex Wawl 🐼 — Thu, 12 Dec 2019 18:23:44 +0000

Hello👋,
My name is Alex and I'm maker of Devmates.co. 😊

Today I want to share problem which was asked by 🏢Google.

Problem:

Given a non-empty array of digits representing a non-negative integer and each element in the array contain a single digit.

Subtract two integers represented as array and return result as array.

You may assume the integer does not contain any leading zero, except the number 0 itself.

Note: Converting to the integer and back to the array is not allowed.

Example:

Input: num1 = [3, 4, 5], num2 = [2,2,1]
Output: [1, 2, 4]

Input: num1 = [1, 0], num2 = [9]
Output: [1]

🙌 Don't hesitate to share your solutions directly on devmates.co

[Devmates.co] Add One by 🚕Bolt

Alex Wawl 🐼 — Wed, 11 Dec 2019 16:13:19 +0000

Hello👋,
My name is Alex and I'm maker of Devmates.co. 😊

Today I want to share problem which was asked by 🚕Bolt.

Problem:

Given a non-empty array of digits representing a non-negative integer and each element in the array contain a single digit.

Add one (1) to this integer and return it as array.

You may assume the integer does not contain any leading zero, except the number 0 itself.

Note: Converting to the integer and back to the array is not allowed.

Example:

Input: [3,2,1]
Output: [3,2,2]

Input: [9,9,9]
Output: [1,0,0,0]

Input: [5,6,9]
Output: [5,7,0]

🙌 Don't hesitate to share your solutions directly on devmates.co

I launch Devmates Challenges, what do you think?

Alex Wawl 🐼 — Fri, 15 Nov 2019 16:26:28 +0000

Hello👋,
My name is Alex and I'm maker of Devmates.co. 😊

We are resolving daily coding problems which asked by top tech companies together. We share our solutions, give some help if anyone stuck, support each other and just hang out together on the internet. 🍻☕️💬

I decided to start working on Challenges because I believe that the best way to learn is learning by doing. So I want to make some challenges on a weekly basis and work on something interesting together. You can collaborate with someone or do everything by yourself.

Challenges - micro-projects where you can learn new technologies, frameworks, languages, API, algorithms, approaches, etc. I hope it gives a chance for juniors developers to practice coding on some real projects. Senior engineers can learn something new by doing.
For example, they can try to resolve it using a new language or framework. Challenges don’t have any language/framework/technology restrictions so you can resolve any problem using any tools.

My motivation is to build a community around it and allow people to learn something new by making small projects. If someone stuck they can ask questions to people who are also working on the same “tasks” and get feedback.

Right now you can see the first challenge named "Conway's Game of Life". It's a kind of classic coding problem that can be implemented in different ways and can be asked in real interviews. It's not just plain "algorithmic" problem, you should visualize it or adding some additional "behavior". It's a kind of "test" version of challenges but in the future, I want to provide more interesting ideas.

So if you are working on some APIs, frameworks, etc let me know. Maybe we can collaborate and I can provide interesting challenges based on your Project. I think it's a great idea and would love to hear your feedback.

I'm working on it in my free time so I would love to hear any ideas about Challenges or about platform at all. It can give me a chance make the platform more useful.
Thanks for reading!

Links:
Main page
Challenges

Introducing Devmates - community of engineers who are solving and sharing solution of Daily Coding Problems.

Alex Wawl 🐼 — Wed, 23 Oct 2019 15:30:03 +0000

Hello👋,
My name is Alex and I'm maker of Devmates.co. 😊

I get these problems from our members or just searching them on the internet(leetcode forums, Glassdoor, teamblind, etc.).
Sometimes this problem can be very easy, sometimes too 👷‍♂️hard, everything depends on skills but we are trying to resolve all of them and Have Fun. 🙌

Nowadays a lot of companies are still asking a huge amount of coding problems which not related to real day job. All the time you have a choice - avoiding companies like this or prepare and try yourself.

I made devmates.co - for engineers who are learning algorithms & data structures or want to prepare for their interviews.

Plans for the future:

I want to add challenges where you can learn "new" tools/frameworks/libraries and share your solutions with others. I love the concept - learning by doing and want to implement it in Devmates.co.

This is the absolute beginning for Devmates.co, so please do let me know your thoughts. There are so many different directions I could take this in and I'd love to hear your ideas.

Feel free to subscribe on Devmates or create your account Here

I look forward to hearing everyone’s feedback! Please share the site with anyone who you think it could help 🙌

[Devmates.co] Candy Crash 📈Bloomberg

Alex Wawl 🐼 — Mon, 14 Oct 2019 07:30:26 +0000

Hello👋,
My name is Alex and I'm maker of Devmates.co. 😊

Today I want to share problem which was asked by 📈Bloomberg.

Problem:

Given a string, reduce the string by removing 3 or more consecutive identical characters. You should greedily remove characters from left to right.

Example:

Input: "aaabbbc"
Output: "c"
Why?:

Remove 3 'a': "aaabbbc" => "bbbc"
Remove 3 'b': "bbbc" => "c"

Input: "aabbbacd"
Output: "cd"
Why?:

Remove 3 'b': "aabbbacd" => "aaacd"
Remove 3 'a': "aaacd" => "cd"

Input: "aabbccddeeedcba"
Output: ""
Why?:

Remove 3 'e': "aabbccddeeedcba" => "aabbccdddcba"
Remove 3 'd': "aabbccdddcba" => "aabbcccba"
Remove 3 'c': "aabbcccba" => "aabbba"
Remove 3 'b': "aabbba" => "aaa"
Remove 3 'a': "aaa" => ""

Input: "aabbccddeeedcba"
Output: ""
Why?:

Remove 3 'e': "aabbccddeeedcba" => "aabbccdddcba"
Remove 3 'd': "aabbccdddcba" => "aabbcccba"
Remove 3 'c': "aabbcccba" => "aabbba"
Remove 3 'b': "aabbba" => "aaa"
Remove 3 'a': "aaa" => ""

[Devmates.co] Group Anagrams 🏨 Booking

Alex Wawl 🐼 — Sat, 05 Oct 2019 08:30:05 +0000

Hello👋,
*My name is Alex and I'm maker of Devmates.co. 😊

Today I want to share problem which was asked by 🏨 Booking.

Problem:

Given an array of strings, group anagrams together.

Example:

Input: ["eat", "tea", "tan", "ate", "nat", "bat"],
Output:
[
["ate","eat","tea"],
["nat","tan"],
["bat"]
]

[Devmates.co] Roman 🏦 Goldman Sachs

Alex Wawl 🐼 — Thu, 03 Oct 2019 08:47:23 +0000

Hello👋,
*My name is Alex and I'm maker of Devmates.co. 😊

Today I want to share problem which was asked by 🏦 Goldman Sachs.

Problem:

Roman numerals are represented by seven different symbols: I, V, X, L, C, D and M

For example, 2 is written as II in Roman numeral, just two one's added together. 12 is written as, XII, which is simply X + II. The number 27 is written as XXVII, which is XX + V + II.

Roman numerals are usually written largest to smallest from left to right. However, the numeral for four is not IIII. Instead, the number four is written as IV. Because the one is before the five we subtract it making four. The same principle applies to the number nine, which is written as IX. There are six instances where subtraction is used:

I can be placed before V (5) and X (10) to make 4 and 9.
X can be placed before L (50) and C (100) to make 40 and 90.
C can be placed before D (500) and M (1000) to make 400 and 900.

Given a Roman numeral, convert it to an integer. Input is guaranteed to be within the range from 1 to 3999.

Example:

Input: "III"
Output: 3

Input: "IX"
Output: 9

Input: "LVIII"
Output: 58

Input: "MCMXCIV"
Output: 1994

[Devmates.co] Product of Array 🍜 Yelp

Alex Wawl 🐼 — Tue, 01 Oct 2019 18:39:01 +0000

Hello👋,
*My name is Alex and I'm maker of Devmates.co. 😊

Today I want to share problem which was asked by 🍜 Yelp.

Problem:

Given non-empty array nums of integers, return an array output such that output[i] is equal to the product of all the elements of nums except nums[i].

Example:

Input: [1,2,3,4]
Output: [1,2,3,4]
Why?
output[0] = 2*3*4 = 24
output[1] = 1*3*4 = 12
output[2] = 1*2*4 = 8
output[3] = 1*2*3 = 6

[Devmates.co] Square Area

Alex Wawl 🐼 — Mon, 30 Sep 2019 08:45:53 +0000

Hello👋,
*My name is Alex and I'm maker of Devmates.co. 😊

Today I want to share problem which was asked by 📦 Amazon.

Problem:

Given a 2D binary matrix filled with 0's and 1's, find the largest square containing only 1's and return its area.

Example:

Input:

1 0 1 0 0
1 0 1 1 1
1 1 1 1 1
1 0 0 1 0

Output: 4

Devmates.co [Array Search]

Alex Wawl 🐼 — Thu, 26 Sep 2019 11:13:44 +0000

Hello👋,
*My name is Alex and I'm maker of Devmates.co. 😊

Today I want to share problem which was asked by 🏢 Google.

Problem:

Find the starting and ending position of a given target value in array of integers nums sorted in ascending order.

If the target is not found in the array, return [-1, -1].

Example:

Input: nums = [3,4,7,7,9,9,9,10], target = 9
Output: [4,6]

Input: nums = [3,4,7,7,9,9,9,10], target = 8
Output: [-1,-1]

Your algorithm's runtime complexity must be in the order of O(log n)