₦airaland Forum

Xedmark:
is this what you call array?

Yes, vectors are dynamic array

namikaze:

from random import randrange

def shuffle(arr):
  for i in range(len(arr)):
    rand_idx = randrange(len(arr))
    arr[rand_idx], arr[i] = arr[i], arr[rand_idx]
  return arr
 
arr = [1,2,3,4,5]
print(shuffle(arr))

Using your python logic in rust, code translate to

fn shuffle(nums: &mut Vec<i32> ) -> Vec<i32> {
    let mut rng = rand::thread_rng();
    for num in 0..nums.len() {
        let x: u32 = rng.gen_range(0..nums.len() as u32);
        nums.swap(num, x as usize);
    }
    return nums.to_vec();
}

This is fucking fast, cause it's using multiple thread and random results are cached

Now I can finally rest and watch the sun set on a great universe

namikaze:
God of bugs
In all seriousness lots of syntax errors and even after fixing the errors does not give the desired output. I bet you typed it on nairaland.

He should have used typescript
Seun need to fix code formatting on Nairaland even if it's only for this section, I mean see Quora see Reddit.

Beans
Chips

ExMI6:
You are an epitome of foolishness softie.
A lesbian This is the height of foolishness.

I think they are still Kids

qtguru:
Everybody that has written it has sworn by it, but I don't know what Project to use it for, what do you use it for or just learning, is it straight forward ?

You can actually use it for anything. To be honest I was left with go or rust which to use for Sys admin stuff and I just picked rust all I use it for now is to write some CMD tool to solve admin task. And since it's cross platform it's also a plus though I still use go sometimes for that.

Though I might no be using the full power but it suites my use case just fine.

namikaze:
Another way to express your solution without the recursion would be;

function shuffle(Array arr) 
{
   HashSet seenIndices = new HashSet()
   Array result = new Array()
   for (int i in 0 to arr.length())
   {
      rand_idx = random num in range(0, arr.length())
      while (seenIndices.contains(rand_idx)
      {
        rand_idx = random num in range(0, arr.length())
      }
      result.add(arr[rand_idx])
      seenIndices.add(rand_idx)
    }
  return result;
}

This I think follows the same idea, but would still depend on the random function, so not recommended.

That's the thing about programming if your solution is not optimised you would know. So there is always room for growth till you move to the next thing.

The randrange you used in python should also depend on random but it's abstracted though am not sure of this.

namikaze:
You should definitely go for walk
You used the hashset to reduce lookup from O(n) to O(1) didn't you? nice one.

Yeah, Things I learnt on leetcode

Also an instance where random() keeps returning an index to a value that's already in the hashset continuously till count gets to zero would yield undesired results.

Yes the complexity is dependent on the random number. So it can be infinite ): so don't try on large dataset.

namikaze:
I remember the Box<T> construct lol, and to think I was able to implement a linkedlist (single) in it I don't think I have the code anymore but I'll check my GitHub later.

Ofcourse it would run fast, rust if fast af. I do think it's not that great to let your algorithm depend on "picking the right number" but I get you.

That's why this code wouldn't work if they we duplicate in the input array. Who knows maybe if I stroll out later the solution might come to my head

namikaze:
Ok, say for instance I called the function on a vector, [1,2,3,4,5];
what would pass as argument for the count parameter?

like this shuffle([1,2,3,4,5], 5);

5 here is the length of the vector.

Amunethseranu:
... Marijuana are we fine? Good I thought u are wise but I was wrong about u
Good bye .

Does your friend also smoke Marijuana? I am interested. Lemme see her picture weda she fine

namikaze:
Sorry, what's the role of the count parameter?

That's the base case of the recursion; if that's not there the code would run forever

namikaze:
My guy even with the unsafe keyword it gets complex real quick, I know what I faced when I tried implementing a doubly linkedlist in Rust, it was crazy. Memory management in C/C++ is much simpler than in Rust.
I agree though learning rust will make you better developer overall.

Guy you're brave, using recursion inside a while loop, I hail thee loolz, well let me see if I can figure out the complexity...

Even on reddit they would advise you not to implement a double linked list or even a Linked list in rust exexpt you wanna run mad But you can use Box<T> to make the running mad slower

My code actually runs fast despite the recursion, it mostly just depends on if it gets the random number right. Best case would be O(n) but that's impossible but it can happen just that the chance are small especially if the input is large.

I'll rewrite this code in C++ so I can test the complexity properly. The lazy_load for HasSet I did up there I don't have the crate for it

TastyFriedPussy:
I'll like to see someone try this with JS

It'll be easy with Js

Amunethseranu:
...
Before time mindsets of d ignorance states that Weeds are synonymous with great & wise thinkers like Galileo , newton, Fela anukpulapo, George orwell, Gandhi when they are alive with them.
When a man starts talking about weed in this form it's a red flag that he will blackmail a female atheist or freethinker because she is weird. U will never in this life date an atheist that's the fact .
FYI I was registered here before most mods in 2009...this is my 4th

You still didn't answer the Question, Why type of weed are you smoking?

namikaze:
Here's something pretty simple, time complexity should be O (n log n), since the time complexity of the randrange function is O (log n).
It's being quite a while since I did anything in rust, I don't want to fight the borrow checker right now Rust used to be my favorite language but it's just too painful to do anything substantial with it, try implementing a doubly linkeldlist in Rust and you'll agree that C++ is easy compared to Rust.

Yeah I agree there are something that are Impossible in rust without using the unsafe key work like i probably did in my code to reduce time & space complexity. But I love the language it makes you as a programmer to be very careful with what you write.

Can you guess the complexity of my code since lookup in a hashmap is O(1) so am thing O(n^2 + random(n)) I don't even know what that means

parkervero:
As a Java dev I can't read the code The while loop is not in addendum to Java way of implementing while loop.

You just have to get used to it to love it

namikaze:

from random import randrange

def shuffle(arr):
  for i in range(len(arr)):
    rand_idx = randrange(len(arr))
    arr[rand_idx], arr[i] = arr[i], arr[rand_idx]
  return arr
  
  
arr = [1,2,3,4,5]
print(shuffle(arr))

Nice one

Ikechukwu183:
As a C++ and Python programmer, I can tell you that this code is not 'readable' by human eyes... is this even a HLL?

That's because Nairaland code formatting is useless.

Amunethseranu:
...
I would have given you to my friend but with ur childish and immature mentality u can only date an atheist girl when she is kidnapped ,forced and bound in chains to date u in captivity because u can never in this life or next date an atheist or freethinker with ur shallow mindset , Go back to ur catholic , Rccg and Chosen girls & wallow in ignorance forever

First of all what type of weed are you smoking? You are probably new on Nairaland.

operAhdam:
e easy pass python

No but way more faster than python

Think4Myself:
Explain the question well, shuffle array as in how?

You never play WHAT before? How them day take shuffle cards. Let's say you have input [1,2,3] you can shuffle it to be [1, 2, 3] or [1, 3, 2] or [3, 1, 2] etc

operAhdam:
that's new,,why do you choose rust boss of all this other languages

Cause it's one of the best programming languages ever, honestly you should try it.

Amunethseranu:
... Do you expect atheists or female light chasers to appear skinny ?

I am not picking them because of their intellectual capacity rather I am picking them because they are less religious or Irreligious. The brain power is none of my business I don't have strength to be arguing with someone am in a relationship with. So yes Have Big nyash in my case sha big boobs and perform the duty of a woman.

Amunethseranu:
...there are many when u seek wisdom instead of nyash

can't I get both?

Truvelisback:
They are in Nairaland too.

Mtcheww!!

She actually looks 12. I don't know what the op was expecting.

OfficialDJ:
I keep telling you all, F^^* all these profile optimization nonsense.

A GREAT PROPOSAL is your pathway to getting jobs on upwork.

Having a great profile with a sucky proposal changes NADA.

I've been upworking for over 7 years now, with an average income of $15,000 monthly, and the above advice will change your life if you utilize it.


Enough said

Make I drop account number?

FalseProphet1:
I see you getting married to a witch.

if I can find witch or mermaid to get married to I'll be very happy

Hismercy20:
is that necessary?

Make people learn na

We are a company looking for carbon developer with 10 years of Experience