search

Earn with igits

Jan 12, 2025 pm 06:12 PM

Earn with igits

Weekly Challenge 303: Python and Perl Solutions

Mohammad S. Anwar's Weekly Challenge provides a regular coding exercise. My solutions, presented below, are initially crafted in Python and then adapted to Perl. This dual approach enhances coding proficiency.

Challenge 303: Solutions

Task 1: Generating Even 3-Digit Integers

Task Description:

Given a list of positive integers, generate all unique even 3-digit integers that can be formed using the digits from the list.

Python Solution:

This Python solution leverages the itertools.permutations function to efficiently generate all possible 3-digit combinations. A set is used to maintain uniqueness.

from itertools import permutations

def three_digits_even(ints: list) -> list:
    solution = set()
    for p in permutations(ints, 3):
        num_str = "".join(map(str, p))
        num = int(num_str)
        if num >= 100 and num % 2 == 0 and num_str[0] != '0':
            solution.add(num)
    return sorted(list(solution))

Perl Solution:

The Perl equivalent uses the Algorithm::Permute module for permutations and a hash to ensure uniqueness.

use Algorithm::Permute;
sub three_digits_even {
    my @ints = @_;
    my %seen;
    my @result;
    my $p = Algorithm::Permute->new(\@ints, 3);
    while (my @perm = $p->next) {
        my $num_str = join('', @perm);
        my $num = $num_str;
        if ($num >= 100 and $num % 2 == 0 and $num_str !~ /^0/) {
            push @result, $num unless $seen{$num}++;
        }
    }
    return sort {$a <=> $b} @result;
}

Examples:

<code># Python
print(three_digits_even([2, 1, 3, 0]))  # Output: [102, 120, 130, 132, 210, 230, 302, 310, 312, 320]
print(three_digits_even([2, 2, 8, 8, 2])) # Output: [222, 228, 282, 288, 822, 828, 882]

# Perl
print "@{[three_digits_even(2, 1, 3, 0)]}\n"; # Output: 102 120 130 132 210 230 302 310 312 320
print "@{[three_digits_even(2, 2, 8, 8, 2)]}\n"; # Output: 222 228 282 288 822 828 882</code>

Task 2: Delete and Earn

Task Description:

Given an array of integers, find the maximum number of points you can earn by repeatedly deleting an element, earning its value, and then deleting all elements with values one less and one more than the deleted element.

Python Solution:

This Python solution uses a Counter to track element frequencies and employs a recursive function to explore different deletion strategies.

from collections import Counter

def delete_and_earn(ints: list) -> int:
    freq = Counter(ints)
    return max_score(freq)

def max_score(freq: Counter) -> int:
    max_points = 0
    for num in list(freq): # Iterate through a copy to safely delete
        points = num * freq[num]
        new_freq = freq.copy()
        del new_freq[num]
        if num - 1 in new_freq:
            del new_freq[num - 1]
        if num + 1 in new_freq:
            del new_freq[num + 1]
        max_points = max(max_points, points + (0 if not new_freq else max_score(new_freq)))
    return max_points

Perl Solution:

The Perl solution mirrors the Python approach using a hash for frequency counting and a recursive function.

sub delete_and_earn {
    my %freq = map { $_ => 1 + $freq{$_} // 0 } @_;
    return max_score(\%freq);
}

sub max_score {
    my $freq = shift;
    my $max_points = 0;
    foreach my $num (keys %$freq) {
        my $points = $num * $freq->{$num};
        my %new_freq = %$freq;
        delete $new_freq{$num};
        delete $new_freq{$num - 1};
        delete $new_freq{$num + 1};
        $max_points = max($max_points, $points + (0 || max_score(\%new_freq)));
    }
    return $max_points;
}

sub max {
    return shift if @_ == 1;
    return $_[0] > $_[1] ? $_[0] : $_[1];
}

Examples:

<code># Python
print(delete_and_earn([3, 4, 2]))  # Output: 6
print(delete_and_earn([2, 2, 3, 3, 3, 4])) # Output: 9

# Perl
print delete_and_earn(3, 4, 2), "\n";  # Output: 6
print delete_and_earn(2, 2, 3, 3, 3, 4), "\n"; # Output: 9</code>

These solutions demonstrate efficient and clear approaches to solving both tasks in the Weekly Challenge 303. The use of both Python and Perl highlights the transferable nature of algorithmic problem-solving across different programming languages.

The above is the detailed content of Earn with igits. For more information, please follow other related articles on the PHP Chinese website!

Statement
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
What are some common operations that can be performed on Python arrays?What are some common operations that can be performed on Python arrays?Apr 26, 2025 am 12:22 AM

Pythonarrayssupportvariousoperations:1)Slicingextractssubsets,2)Appending/Extendingaddselements,3)Insertingplaceselementsatspecificpositions,4)Removingdeleteselements,5)Sorting/Reversingchangesorder,and6)Listcomprehensionscreatenewlistsbasedonexistin

In what types of applications are NumPy arrays commonly used?In what types of applications are NumPy arrays commonly used?Apr 26, 2025 am 12:13 AM

NumPyarraysareessentialforapplicationsrequiringefficientnumericalcomputationsanddatamanipulation.Theyarecrucialindatascience,machinelearning,physics,engineering,andfinanceduetotheirabilitytohandlelarge-scaledataefficiently.Forexample,infinancialanaly

When would you choose to use an array over a list in Python?When would you choose to use an array over a list in Python?Apr 26, 2025 am 12:12 AM

Useanarray.arrayoveralistinPythonwhendealingwithhomogeneousdata,performance-criticalcode,orinterfacingwithCcode.1)HomogeneousData:Arrayssavememorywithtypedelements.2)Performance-CriticalCode:Arraysofferbetterperformancefornumericaloperations.3)Interf

Are all list operations supported by arrays, and vice versa? Why or why not?Are all list operations supported by arrays, and vice versa? Why or why not?Apr 26, 2025 am 12:05 AM

No,notalllistoperationsaresupportedbyarrays,andviceversa.1)Arraysdonotsupportdynamicoperationslikeappendorinsertwithoutresizing,whichimpactsperformance.2)Listsdonotguaranteeconstanttimecomplexityfordirectaccesslikearraysdo.

How do you access elements in a Python list?How do you access elements in a Python list?Apr 26, 2025 am 12:03 AM

ToaccesselementsinaPythonlist,useindexing,negativeindexing,slicing,oriteration.1)Indexingstartsat0.2)Negativeindexingaccessesfromtheend.3)Slicingextractsportions.4)Iterationusesforloopsorenumerate.AlwayschecklistlengthtoavoidIndexError.

How are arrays used in scientific computing with Python?How are arrays used in scientific computing with Python?Apr 25, 2025 am 12:28 AM

ArraysinPython,especiallyviaNumPy,arecrucialinscientificcomputingfortheirefficiencyandversatility.1)Theyareusedfornumericaloperations,dataanalysis,andmachinelearning.2)NumPy'simplementationinCensuresfasteroperationsthanPythonlists.3)Arraysenablequick

How do you handle different Python versions on the same system?How do you handle different Python versions on the same system?Apr 25, 2025 am 12:24 AM

You can manage different Python versions by using pyenv, venv and Anaconda. 1) Use pyenv to manage multiple Python versions: install pyenv, set global and local versions. 2) Use venv to create a virtual environment to isolate project dependencies. 3) Use Anaconda to manage Python versions in your data science project. 4) Keep the system Python for system-level tasks. Through these tools and strategies, you can effectively manage different versions of Python to ensure the smooth running of the project.

What are some advantages of using NumPy arrays over standard Python arrays?What are some advantages of using NumPy arrays over standard Python arrays?Apr 25, 2025 am 12:21 AM

NumPyarrayshaveseveraladvantagesoverstandardPythonarrays:1)TheyaremuchfasterduetoC-basedimplementation,2)Theyaremorememory-efficient,especiallywithlargedatasets,and3)Theyofferoptimized,vectorizedfunctionsformathematicalandstatisticaloperations,making

See all articles

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

WebStorm Mac version

WebStorm Mac version

Useful JavaScript development tools

mPDF

mPDF

mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),

EditPlus Chinese cracked version

EditPlus Chinese cracked version

Small size, syntax highlighting, does not support code prompt function

DVWA

DVWA

Damn Vulnerable Web App (DVWA) is a PHP/MySQL web application that is very vulnerable. Its main goals are to be an aid for security professionals to test their skills and tools in a legal environment, to help web developers better understand the process of securing web applications, and to help teachers/students teach/learn in a classroom environment Web application security. The goal of DVWA is to practice some of the most common web vulnerabilities through a simple and straightforward interface, with varying degrees of difficulty. Please note that this software

SublimeText3 English version

SublimeText3 English version

Recommended: Win version, supports code prompts!