qtguru:


Oh I see, let's benchmark it with a high length of array and see what the time difference will be. Can you share a link ?

NOTE: @GREATIGBOMAN, I see devdevdev's point, the constant is n (Length of Array), if there are 5 million items, you will loop 5 million times, that's a brute force, but I don't think it's room for argument, it's an opportunity to provide alternative algo that is efficient.

Let's not argue and look at efficient runtime. I will join you guys soon, this week or next.

GREATIGBOMAN:



She's just trying to get back at me for pointing out her pile of trash on one of her threads.

qtguru:


I don't think it's that, your time complexity is kinda Quadratic, you have 2 loops for an n length of array, O(n^ 2), which will really take a lot of time if the input gets large.

GREATIGBOMAN:


Ok.

But based on the question asked does that render my solution wrong or inefficient?

GREATIGBOMAN:


Ok.

But based on the question asked does that render my solution wrong or inefficient?

qtguru:


It depends, most algorithm target efficient and correctness. Brute force at least you know you are right, but as devdevdev mentioned, input gets large overnight, so an efficient algorithm is usually favored.

I don't want you guys to fight, I think the debate between you two is healthy for suggesting faster solutions.

Shalom.

Devdevdev:


No interviewer will pass your slow solution, olodo. It is slow, inefficient and plain lazy for someone claiming to be an experienced programmer.

Imagine implementing your solution on a large data set. It will take your app hours to load. Mine will take milli seconds. If you can't see the difference then you are irredeemably daft.

Devdevdev:


No interviewer will pass your slow solution, olodo. It is slow, inefficient and plain lazy for someone claiming to be an experienced programmer.

Imagine implementing your solution on a large data set. It will take your app hours to load. Mine will take milli seconds. If you can't see the difference then you are irredeemably daft.

qtguru:


Please no need for insults we are all learning, else the purpose of this thread will be defeated.

Devdevdev:


No interviewer will pass your solution, olodo. It is slow, inefficient and plain lazy for someone claiming to be an experienced programmer.

Imagine implementing your solution on a large data set. It will take your app hours to load. Mine will take milli seconds. If you can't see the difference then you are irredeemably daft.

Devdevdev:


The person I "insulted" denigrated me when I asked a simple question two months ago when I was still in the beginning stages of my learning. But now I have improved beyond my expectations and can build complex apps from scratch on my own using vanilla Js and reactJs. I've also been practicing DSAs like a mad woman.

He called me a failure because I had trouble fetching data from an API, but here he is two months later, unable to solve a simple algorithm question. How the tables have turned. He deserves all the insults.

namikaze:

with recursive dfs
jdoodle.com/ia/C7K

map = {
    '2':"abc",'3':"def",'4':"ghi",
    '5':"jkl", '6':"mno",'7':"pqrs",
    '8':"tuv",'9':"wxyz"
}
 
def letterCombinations(s, cur="", res=[]):
  if s == "":
    res.append(cur)
    return 
 
  n, s = s[0], s[1:]
  for adj in map[n]:
    letterCombinations(s, cur+adj, res)
    
  return res
  

s = "23"
print(letterCombinations(s))

Sleekcode:
Letter Combinations of a Phone Number
Given a string containing digits from 2-9 inclusive, return all possible letter combinations that the number could represent.

A mapping of digit to letters (just like on the telephone buttons) is given below. Note that 1 does not map to any letters.




Example:
Javascript solution

https://jdoodle.com/ia/C7U

nested loops... before you come for my head... they are different methods to solve this question, one of such is using a recursive function.

simply use the one you're most comfortable with.



Input: "23"
Output: ["ad", "ae", "af", "bd", "be", "bf", "cd", "ce", "cf"].
Note:

Although the above answer is in lexicographical order, your answer could be in any order you want.

Difficulty= Medium

Sleekcode:
Letter Combinations of a Phone Number
Given a string containing digits from 2-9 inclusive, return all possible letter combinations that the number could represent.

A mapping of digit to letters (just like on the telephone buttons) is given below. Note that 1 does not map to any letters.




Example:




Input: "23"
Output: ["ad", "ae", "af", "bd", "be", "bf", "cd", "ce", "cf"].
Note:

Although the above answer is in lexicographical order, your answer could be in any order you want.

Difficulty= Medium

Devdevdev:


No interviewer will pass your solution, olodo. It is slow, inefficient and plain lazy for someone claiming to be an experienced programmer.

Imagine implementing your solution on a large data set. It will take your app hours to load. Mine will take milli seconds. If you can't see the difference then you are irredeemably daft.

GREATIGBOMAN:


Ok.

But based on the question asked does that render my solution wrong or inefficient?

Najdorf:

The whole point of DSA is solving problems as efficiently as possible

AlchemyOfCodes:
Omo thread don turn war-zone. Me wey I just dey reason to post my spaghetti code. Anyway I go still post am sha. Insult no dey kee person

Devdevdev:


You still don't want to accept that your solution is slow and will give you a FAIL in an interview.

Ordinary this simple algorithm question and you can't provide an efficient solution. How will you now solve harder questions efficiently?

Set awon Nairaland troll. Maybe if you invest all the time you use in trolling and insulting people into practicing DSA questions, you'll get better. You are still at level zero. Providing brute force solution to ordinary Two Sum question.

It's clear that all my hard work is paying off. The more knowledgeable I become the more I realize just how much of a quack people like you are. Continue trolling Nairaland from morning till night while I invest my time improving my coding skills.

Najdorf:

The whole point of DSA is solving problems as efficiently as possible

Sleekcode:


You don't just suddenly understand everything to the point of solving all the problems.


If you start solving from the very basics, you'd see yourself solving medium difficult questions in few months time

GREATIGBOMAN:
Longest Palindromic Substring


Given a string s, find the longest palindromic substring in s. You may assume that the maximum length of s is 1000.

Example 1:

Input: "babad"
Output: "bab"

Note: "aba" is also a valid answer.

Example 2:

Input: "cbbd"
Output: "bb"

Difficulty:

Medium

GREATIGBOMAN:


Javascript solution

https://jdoodle.com/ia/C7U

nested loops... before you come for my head... they are different methods to solve this question, one of such is using a recursive function.

simply use the one you're most comfortable with.

GREATIGBOMAN:
Longest Palindromic Substring


Given a string s, find the longest palindromic substring in s. You may assume that the maximum length of s is 1000.

Example 1:

Input: "babad"
Output: "bab"

Note: "aba" is also a valid answer.

Example 2:

Input: "cbbd"
Output: "bb"

Difficulty:

Medium