Create sub-lists from input | Code Society | Page 1

proper cradle Feb 14, 2023, 6:17 AM

#

#

Entré = input
Résultat = Result (output)

The input must be on one line and the output must be displayed as the image. The values can be any length and any numbers

other examples

# input
5 1

# output
[5]
[1]
[5, 1]

# input
53 12 79 21 51 87

# output
[53]
[12]
[79]
[21]
[51]
[87]
[53, 12]
[12, 79]
[79, 21]
[21, 51]
[51, 87]
[53, 12, 79]
[12, 79, 21]
[79, 21, 51]
[21, 51, 87]
[53, 12, 79, 21]
[12, 79, 21, 51]
[79, 21, 51, 87]
[53, 12, 79, 21, 51]
[12, 79, 21, 51, 87]
[53, 12, 79, 21, 51, 87]

# input
6 1 82313

# output
[6]
[1]
[82313]
[6, 1]
[1, 82313]
[6, 1, 82313]

#

Create sub-lists from input

cursive phoenix Feb 14, 2023, 6:25 AM

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proper cradle

each element have 2 choices:

Include it in the sublist
Ignore it

proper cradle Feb 14, 2023, 6:27 AM

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No they need to be included. You need to take in input multiple numbers (on the same line) and generate a list like shown in the image.

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The values can be any numbers

cursive phoenix Feb 14, 2023, 6:29 AM

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proper cradle No they need to be included. You need to take in input multiple numbers (on the ...

yea Ik, what I mean is for example in the 1st sublist only 1 is included, 2, 3, and 4 are all excluded

proper cradle Feb 14, 2023, 6:29 AM

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Yea

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But that's the thing, it's not 1, it's the first value

cursive phoenix Feb 14, 2023, 6:30 AM

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proper cradle But that's the thing, it's not 1, it's the first value

yea Ik

fringe geode Feb 14, 2023, 7:16 AM

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Submit where?

proper cradle Feb 14, 2023, 7:23 AM

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You can send it to me or here and obfuscated (although DM would be better for now)

cursive phoenix Feb 14, 2023, 8:49 AM

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cursive phoenix each element have 2 choices: 1) Include it in the sublist 2) Ignore it

oh I just noticed my idea is wrong, it's sublist I thought it as subsets 💀

novel vine Feb 14, 2023, 9:03 AM

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One can use 2 pointers method to solve it i think the time complexity would be O(n^2) though

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Ill implement it once i come home

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I cant think of a dp soln though

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Only 2 pointer sliding through the array would be the only soln i think

strange dove Feb 14, 2023, 2:52 PM

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I think the solution I have in mind would be O(n^3) hmm

proper cradle Feb 14, 2023, 4:20 PM

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strange dove I think the solution I have in mind would be O(n^3) hmm

Do it like you can, then optimise it if necessary

strange dove Feb 14, 2023, 4:45 PM

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proper cradle Do it like you can, then optimise it if necessary

yeah I'll write it when I get home xD In the meanwhile I think about it

novel vine Feb 14, 2023, 5:54 PM

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the implementation i though of doesnt work in cpp

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it might work in python using list indexing

proper cradle Feb 14, 2023, 5:55 PM

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You can do it in Python if you want too

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I did this exercise in a few languages such as Python

novel vine Feb 14, 2023, 5:58 PM

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Ive thought of another approach

novel vine Feb 14, 2023, 6:16 PM

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will take me a day i suppose but ill do it

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wont be able to do it today

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have work to do

strange dove Feb 14, 2023, 10:37 PM

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alright I have my O(n^3) solution coded

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I just need to find a way to optimize it

strange dove Feb 14, 2023, 11:04 PM

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is it even possible to do it O(n^2)?

proper cradle Feb 14, 2023, 11:07 PM

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You can send it to me if you want and I might be able to give you some pointers if I can

And yes you can do it in O(n^2)

strange dove Feb 14, 2023, 11:08 PM

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sure

novel vine Feb 16, 2023, 6:29 PM

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My algorithm itself is O(n^3)

strange dove Feb 17, 2023, 5:49 PM

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@proper cradle after testing both of my algorithm, it looks like my first algo is better than my second lol

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I dont remember the formula to get the right exponent tho

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its probably n^2ish

frosty fjord Mar 31, 2023, 11:31 PM

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it's recursive like C(n,k) probability sets

tepid maple Nov 30, 2023, 8:46 PM

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||```java
public static void main(String[] args) {
Scanner input = new Scanner(System.in);

    String[] input = inout.nextLine().split();

    int i = input.length;
    while (i > 0) {

        for (int j = 0; j < i; j++) {

            if ((input.length - i) > 0) {
                System.out.print("[");
                for (int k = 0; k < (input.length - i + 1); k++) {

                    System.out.print(input[j + k]);
                    if (k != (input.length - i)) {
                        System.out.print(", ");
                    }
                }
                System.out.println("]");
            } else {
                System.out.println("[" + input[j] + "]");
            }

        }
        i--;
    }

}

o(n**3) solution, iimma try to make it better brb
nvm, I'm too lazy to make it better
||

proper cradle Nov 30, 2023, 9:09 PM

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tepid maple ||```java public static void main(String[] args) { Scanner input = new S...

You didn't respect the input requirements tho

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The input must be on one line
It's supposed to be a string that a user enters. You can't do inputs with the compiler bot but it still needs to come from a string

Ex.

String input = "5 1";

And you can simplify this

tepid maple Dec 1, 2023, 5:53 AM

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oopsie

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I know it probably is possible to simplify it to be less verbose, haven't looked it that much

proper cradle Dec 1, 2023, 6:09 AM

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tepid maple I know it probably is possible to simplify it to be less verbose, haven't looked...

Hint: You can use java.util.Arrays to simplify some things and you can solve the problem with 2 for loops and no ifs.

tepid maple Dec 1, 2023, 6:13 AM

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that would be making arrays inside of that Array to consist the indexes the new list that has to be constructed by?

proper cradle Dec 1, 2023, 6:14 AM

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I don't understand what you're saying but yes?

tepid maple Dec 1, 2023, 6:15 AM

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I assume I would create like a blueprint on how to make the sublists (marked by indexes) into that Arrays object?

proper cradle Dec 1, 2023, 6:17 AM

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No

tepid maple Dec 1, 2023, 6:50 AM

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then I'm not sure what you're referring to

proper cradle Dec 1, 2023, 6:51 AM

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java.util.Arrays is a class containing utility functions for arrays.

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If you use some of those, (I have 2 in mind) you can simplify everything a lot.

For the second part, you can simplify the core logic of the solution by using only 2 for loops and not ifs

frosty fjord Dec 11, 2023, 4:49 AM

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tepid maple ||```java public static void main(String[] args) { Scanner input = new S...

obvious compilation typo errors 😂
with input and inout

frosty fjord Dec 11, 2023, 5:12 AM

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;compile java
||

import java.util.*;

public class TestSubList
{
  public static void printShiftList(
    final List<String> list, final int amount)
  {
    if (list == null) { System.out.println("[]"); return; }

    final int n = list.size();
    if (n == amount)
    {
      System.out.println(list);
    }
    else
    {
      for(int i = 0; i < n; ++i)
      {
        final int toIndex = i + amount;
        if (toIndex <= n)
        {
          final List<String> subList = list.subList(i, toIndex);
          System.out.println(subList);
        }
      }
    }
  }

  public static void printShiftList(final String input0)
  {
    final String input = (input0 == null) ? "" : input0.trim();

    System.out.println("# input");
    System.out.println(input);

    final String[] arr = input.split("\\s+");
    final List<String> list = Arrays.asList(arr);

    System.out.println("");
    System.out.println("# output");

    final int n = list.size();
    for(int i = 1; i <= n; ++i)
    {
      printShiftList(list, i);
    }

    System.out.println("");
  }

  // Test cases
  public static void main(String[] args)
  {
    final String input1234 = "1 2 3 4";
    printShiftList(input1234);

    final String input53 = "53 12 79 21 51 87";
    printShiftList(input53);

    final String input51 = "5 1";
    printShiftList(input51);

    final String input82 = "6 1 82313";
    printShiftList(input82);

    final String inputEmpty = "";
    printShiftList(inputEmpty);

    final String input5 = "5";
    printShiftList(input5);
  }
}

||

gloomy hillBOT Dec 11, 2023, 5:12 AM

#

Program Output

# input
1 2 3 4

# output
[1]
[2]
[3]
[4]
[1, 2]
[2, 3]
[3, 4]
[1, 2, 3]
[2, 3, 4]
[1, 2, 3, 4]

# input
53 12 79 21 51 87

# output
[53]
[12]
[79]
[21]
[51]
[87]
[53, 12]
[12, 79]
[79, 21]
[21, 51]
[51, 87]
[53, 12, 79]
[12, 79, 21]
[79, 21, 51]
[21

frosty fjord Dec 11, 2023, 5:13 AM

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Works for all use cases 🙂 and null / empty cases

#

You forgot to mention if you wanted just print or return List<List<String>>

#

If you want a Scanner version I could wrap that into also

#

;compile java
||

import java.util.*;

public class TestSubList2
{
  public static <V> void printShiftList(final List<V> list, final int amount, final List<List<V>> output)
  {
    if (list == null)
    {
      System.out.println("[]");
      output.add(Collections.<V>emptyList());
      return;
    }

    final int n = list.size();
    if (n == amount)
    {
      System.out.println(list);
      output.add(list);
    }
    else
    {
      for(int i = 0; i < n; ++i)
      {
        final int toIndex = i + amount;
        if (toIndex <= n)
        {
          final List<V> subList = list.subList(i, toIndex);
          System.out.println(subList);
          output.add(subList);
        }
      }
    }
  }

  public static void printShiftList(final String input0)
  {
    final String input = (input0 == null) ? "" : input0.trim();

    System.out.println("# input");
    System.out.println(input);

    final String[] arr = input.split("\\s+");
    final List<String> list = Arrays.asList(arr);

    System.out.println("");
    System.out.println("# output");

    final int n    = list.size();
    final int half = n / 2;
    final int size = n * half + half;

    final List< List<String> > output = new ArrayList< List<String> >(size);
    for(int i = 1; i <= n; ++i)
    {
      printShiftList(list, i, output);
    }

    System.out.println("");
    System.out.println("# result");
    System.out.println("" + output);
    System.out.println("");

    assert(output.size() == size);
  }

  // Test cases
  public static void main(String[] args)
  {
    final String input1234 = "1 2 3 4";
    printShiftList(input1234);

    final String input53 = "53 12 79 21 51 87";
    printShiftList(input53);

    final String input51 = "5 1";
    printShiftList(input51);

    final String input82 = "6 1 82313";
    printShiftList(input82);

    final String inputEmpty = "";
    printShiftList(inputEmpty);

    final String input5 = "5";
    printShiftList(input5);
  }
}

||

gloomy hillBOT Dec 11, 2023, 5:25 AM

#

Program Output

# input
1 2 3 4

# output
[1]
[2]
[3]
[4]
[1, 2]
[2, 3]
[3, 4]
[1, 2, 3]
[2, 3, 4]
[1, 2, 3, 4]

# result
[[1], [2], [3], [4], [1, 2], [2, 3], [3, 4], [1, 2, 3], [2, 3, 4], [1, 2, 3, 4]]

# input
53 12 79 21 51 87

# output
[53]
[12]
[79]
[21]
[51]
[

frosty fjord Dec 11, 2023, 5:26 AM

#

Funnily, I found this criteria:

int half = n / 2;          
int output_size = n * half + half;

#

my solution is O(n²)

#

Total complexity probably something like:
O(n²/2 + 3n/2)
including the splitting part.

Excluding splitting, where List<V> is provided:
O(n²/2 + n/2)

#

Also, subList() in JDK5+ is a "free SubList proxy class" or O(1)
i.e.: no element copy required
https://github.com/eagle518/jdk-source-code/blob/master/jdk5.0_src/j2se/src/share/classes/java/util/AbstractList.java#L860

GitHub

jdk-source-code/jdk5.0_src/j2se/src/share/classes/java/util/Abstrac...

Automatically exported from code.google.com/p/jdk-source-code - eagle518/jdk-source-code

frosty fjord Dec 12, 2023, 2:43 AM

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Had less sucess with the Perl5 translation from Java 😦

frosty fjord Dec 12, 2023, 6:00 AM

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;compile php
||

<?php
function printDumpArray2D($output){
  print "[\n";
  foreach($output as $i => $list){
    print ($i == 0) ? "\t" : ",\n\t";
    printDumpArray($list);
  }
  print "\n]\n";
}

function printDumpArray($list){
  print "[ ";
  print implode(', ', $list);
  print " ]";
}

function printShiftListItem($list, $amount, $output){
  if (!is_array($list)){
    $arr = array();
    printDumpArray($arr);
    print("\n");
    array_push($output, $arr);
    return $output;
  }

  $n = count($list);
  if ($n == $amount){
    printDumpArray($list);
    print("\n");
    array_push($output, $list);
  }else{
    for($i = 0; $i < $n; ++$i){
      $toIndex = $i + $amount;
      if ($toIndex <= $n){
        $subList = array_slice($list, $i, $amount);
        printDumpArray($subList);
        print("\n");
        array_push($output, $subList);
      }
    }
  }

  return $output;
}

function printShiftList($input0){
  $input = (!is_string($input0)) ? "" : trim($input0);
  print("# input\n");
  print($input);
  print("\n");
  $list = preg_split("/[\s,]+/", $input);

  print("\n");
  print("# output\n");

  $n    = count($list);
  $half = $n / 2;
  $size = $n * $half + $half;

  $output = array();
  for($i = 1; $i <= $n; ++$i){
    $output = printShiftListItem($list, $i, $output);
  }

  print("\n");
  print("# result");
  print("\n");
  printDumpArray2D($output);
  print("\n");

  return $output;
}

function main(){
$input1234 = "1 2 3 4";
printShiftList($input1234);

$input53 = "53 12 79 21 51 87";
printShiftList($input53);

$input51 = "5 1";
printShiftList($input51);

$input82 = "6 1 82313";
printShiftList($input82);

$inputEmpty = "";
printShiftList($inputEmpty);

$input5 = "5";
printShiftList($input5);
}
main();exit();

||

gloomy hillBOT Dec 12, 2023, 6:00 AM

#

Program Output

# input
1 2 3 4

# output
[ 1 ]
[ 2 ]
[ 3 ]
[ 4 ]
[ 1, 2 ]
[ 2, 3 ]
[ 3, 4 ]
[ 1, 2, 3 ]
[ 2, 3, 4 ]
[ 1, 2, 3, 4 ]

# result
[
[ 1 ],
[ 2 ],
[ 3 ],
[ 4 ],
[ 1, 2 ],
[ 2, 3 ],
[ 3, 4 ],
[ 1, 2, 3 ],
[ 2, 3, 4 ],
[ 1, 2, 3, 4 ]
]

# input
53 12 79 21

frosty fjord Dec 12, 2023, 6:45 AM

#

||

<html><body><pre><script>
function printDumpArray2D(output){
  var i=0,n=output ? +output.length : 0,list=[];
  document.write("\n[\n");
  for(;i<n;++i){
    document.write( (i == 0) ? "\t" : ",\n\t" );
    list = output[i];
    printDumpArray(list,true);
  }
  document.write("\n]\n");
}

function printDumpArray(list,nl){
  document.write("[ ");
  if (list && +list.length) document.write( list.join(', ') );
  document.write(" ]");
  document.write(nl ? "" : "\n");
}

function printShiftListItem(list, amount, output){
  if (!list){
    var arr = [];
    printDumpArray(arr);
    output.push(arr);
    return output;
  }

  var n = list ? +list.length : 0;
  if (n == amount){
    printDumpArray(list);
    output.push(list);
    return output;
  }else{
    for(var i = 0; i < n; ++i){
      var toIndex = i + amount;
      if (toIndex <= n){
        var subList = list.slice(i, toIndex);
        printDumpArray(subList);
        output.push(subList);
      }
    }
  }
  return output;
}

function printShiftList(input0){
  var input = !input0 ? "" : input0.replace(/^\s+|\s+$/gm,'');
  document.write("# input\n");
  document.write(input);
  document.write("\n");

  var list = input.split(/[\s,]+/);
  document.write("\n");
  document.write("# output\n");

  var n    = list ? +list.length : 0;
  var half = n / 2;
  var size = n * half + half;
  var output = [];
  for(var i = 1; i <= n; ++i){
    output = printShiftListItem(list, i, output);
  }

  document.write("\n");
  document.write("# result");
  document.write("\n");
  printDumpArray2D(output);
  document.write("\n");

  return output;
}
;!(function(){
  var input1234 = "1 2 3 4";
  printShiftList(input1234);

  var input53 = "53 12 79 21 51 87";
  printShiftList(input53);

  var input51 = "5 1";
  printShiftList(input51);

  var input82 = "6 1 82313";
  printShiftList(input82);

  var inputEmpty = "";
  printShiftList(inputEmpty);

  var input5 = "5";
  printShiftList(input5);
})();
</script>

||

#

JavaScript browser version 😄 (works in IE11+)

bold ferry Mar 23, 2024, 6:51 PM

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@proper cradle i dont get it

proper cradle Mar 23, 2024, 10:38 PM

#

bold ferry <@310386501483757570> i dont get it

Can you expand a bit on that? What don't you understand exactly?

bold ferry Mar 23, 2024, 10:39 PM

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proper cradle Can you expand a bit on that? What don't you understand exactly?

i dont get what the question is asking for

proper cradle Mar 23, 2024, 11:15 PM

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bold ferry i dont get what the question is asking for

Okay... Basically, you're getting mulitple values as input and create a series of lists, each containing a subset of the values. The lists are generated in a specific order. Each individual number from the input sequence is output as a single-element list, then pairs of consecutive numbers, then triplets and so on until you reach a list of the size of the input values.

So, if you have 4 values, you will have 4 sub-lists of 1 value, then 3 sub-lists of 2, then 2 of 3 and finally 1 of 4

#

I am unsure what to add tbh. Look at the examples if you didn't, they should help.

bold ferry Mar 23, 2024, 11:51 PM

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proper cradle Okay... Basically, you're getting mulitple values as input and create a series o...

ohhhh okay. ill do that easy

proper cradle Mar 24, 2024, 1:33 PM

#

bold ferry ohhhh okay. ill do that easy

Have you been able to understand and/or do it?

bold ferry Mar 24, 2024, 1:59 PM

#

proper cradle Have you been able to understand and/or do it?

i havent tried, ive been drawingnandbwatching anime. ill give it a shot next tine im feeling like coding

bold ferry Mar 25, 2024, 6:16 PM

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proper cradle Have you been able to understand and/or do it?

nice and easy

#

||```py
list_ = [1,4,3,6]
for i in range(len(list_)):
for n in range(len(list_)-i):
print(list_[n:n+i+1])

5 minute job

proper cradle Mar 25, 2024, 11:15 PM

#

bold ferry nice and easy

Well... As stated in the problem, it needs to initially take a user input that as to be a string with values separated by spaces which has to be formatted then passed to a function to generate the sublists. The general idea is there though.

After that, if you want a harder one you can try https://discord.com/channels/823178343943897088/1105321678667522090

proper cradle Mar 25, 2024, 11:22 PM

#

proper cradle Well... As stated in the problem, it needs to initially take a user input that a...

Just to be sure you saw it, I edited my message @bold ferry

bold ferry Mar 25, 2024, 11:24 PM

#

proper cradle Well... As stated in the problem, it needs to initially take a user input that a...

okay so replace line 1 with:

list_ = input()
list_.split(" ")

#

?

proper cradle Mar 25, 2024, 11:26 PM

#

You do it like you want but yes

#

Fyi, using list_ is a really bad name.

bold ferry Mar 25, 2024, 11:26 PM

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;-; well i was gonna call it list but thats a function in python

proper cradle Mar 25, 2024, 11:27 PM

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Yea, that's because calling it list is a bad name too haha

bold ferry Mar 25, 2024, 11:27 PM

#

damnm

#

lst?

proper cradle Mar 25, 2024, 11:27 PM

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That's worst

bold ferry Mar 25, 2024, 11:27 PM

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😭 i use lst all the time

proper cradle Mar 25, 2024, 11:27 PM

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Names should describe what the variable is used for or contains

#

And generally, they are plural

#

For example, a list contains user could be called users.

#

In this case, it contains what? Values? Elements? Numbers (although if well made it could handle other type than numbers), etc

bold ferry Mar 25, 2024, 11:30 PM

#

proper cradle Just to be sure you saw it, I edited my message <@668233720481710107>

i think i just finished the other problem

#

lemme test rq, i promise im listening

proper cradle Mar 25, 2024, 11:33 PM

#

proper cradle In this case, it contains what? Values? Elements? Numbers (although if well made...

The point is simply use "Intention-Revealing Names"

bold ferry Mar 25, 2024, 11:34 PM

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proper cradle The point is simply use "Intention-Revealing Names"

okay gotcha

#

also idk where i went wrong on this other problem lmao but its WRONG

proper cradle Mar 25, 2024, 11:34 PM

#

I recommend reading "clean code" by Robert C Martin. This a small overview of the naming section of it

bold ferry Mar 25, 2024, 11:35 PM

#

print(smallest(261235))
print(smallest(209917))
print(smallest(285365))
print(smallest(269045))
print(smallest(296837))

#

[1216121315, 2, 4]
[209090107, 1, 4]
[2825232625, 0, 4]
[206090405, 3, 4]
[2926282327, 0, 4]

#

sad2

proper cradle Mar 25, 2024, 11:57 PM

#

Please use the https://discord.com/channels/823178343943897088/1105321678667522090

#Create sub-lists from input