Merge pull request #7715 from LubosKolouch/master

Challenge 007 008 LK Perl Python

8 files changed, 243 insertions, 0 deletions

diff --git a/challenge-007/lubos-kolouch/perl/ch-1.pl b/challenge-007/lubos-kolouch/perl/ch-1.pl
new file mode 100644
index 0000000000..9c583cee75
--- /dev/null
+++ b/challenge-007/lubos-kolouch/perl/ch-1.pl
@@ -0,0 +1,21 @@
+use strict;
+use warnings;
+
+# Function to calculate the sum of digits
+sub sum_of_digits {
+    my $number = shift;
+    my $sum    = 0;
+    while ( $number > 0 ) {
+        $sum += $number % 10;
+        $number = int( $number / 10 );
+    }
+    return $sum;
+}
+
+# Main program
+for my $num ( 0 .. 50 ) {
+    my $sum = sum_of_digits($num);
+    if ( $sum > 0 && $num % $sum == 0 ) {
+        print "$num\n";
+    }
+}
diff --git a/challenge-007/lubos-kolouch/perl/ch-2.pl b/challenge-007/lubos-kolouch/perl/ch-2.pl
new file mode 100644
index 0000000000..84b3903e8d
--- /dev/null
+++ b/challenge-007/lubos-kolouch/perl/ch-2.pl
@@ -0,0 +1,42 @@
+#!/usr/bin/perl
+use strict;
+use warnings;
+
+sub find_shortest_ladder {
+    my ( $word1, $word2, @wordlist ) = @_;
+
+    # Check if input words are valid
+    my $wordlen = length($word1);
+    my %wordset = map { $_ => 1 } @wordlist;
+    unless ( $wordset{$word1} && $wordset{$word2} && length($word2) == $wordlen ) {
+        return ();
+    }
+
+    # Use breadth-first search to find shortest ladder
+    my @queue   = [ $word1, [$word1] ];
+    my %visited = ( $word1 => 1 );
+    while (@queue) {
+        my ( $word, $path ) = @{ shift(@queue) };
+        for my $i ( 0 .. $wordlen - 1 ) {
+            for my $char ( 'a' .. 'z' ) {
+                my $newword = substr( $word, 0, $i ) . $char . substr( $word, $i + 1 );
+                if ( $newword eq $word2 ) {
+                    return [ @$path, $word2 ];
+                }
+                if ( $wordset{$newword} && !$visited{$newword} ) {
+                    push @queue, [ $newword, [ @$path, $newword ] ];
+                    $visited{$newword} = 1;
+                }
+            }
+        }
+    }
+
+    # If no ladder is found, return empty list
+    return ();
+}
+
+# Test cases
+my @wordlist = ( 'cold', 'cord', 'core', 'care', 'card', 'ward', 'warm', 'worm' );
+my $ladder   = find_shortest_ladder( 'cold', 'warm', @wordlist );
+my $expected = [ 'cold', 'cord', 'card', 'ward', 'warm' ];
+die "Test case 1 failed" unless ( join( ',', @$ladder ) eq join( ',', @$expected ) );
diff --git a/challenge-007/lubos-kolouch/python/ch-1.py b/challenge-007/lubos-kolouch/python/ch-1.py
new file mode 100644
index 0000000000..02a91e9edf
--- /dev/null
+++ b/challenge-007/lubos-kolouch/python/ch-1.py
@@ -0,0 +1,22 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+def sum_of_digits(number: int) -> int:
+    """Return the sum of digits of a given number."""
+    total = 0
+    while number > 0:
+        total += number % 10
+        number //= 10
+    return total
+
+
+def print_niven_numbers() -> None:
+    """Print all the niven numbers from 0 to 50 inclusive."""
+    for num in range(51):
+        digit_sum = sum_of_digits(num)
+        if digit_sum != 0 and num % digit_sum == 0:
+            print(num)
+
+
+if __name__ == '__main__':
+    print_niven_numbers()
diff --git a/challenge-007/lubos-kolouch/python/ch-2.py b/challenge-007/lubos-kolouch/python/ch-2.py
new file mode 100644
index 0000000000..29aaf2ccce
--- /dev/null
+++ b/challenge-007/lubos-kolouch/python/ch-2.py
@@ -0,0 +1,48 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+from typing import List, Tuple
+
+
+def find_shortest_ladder(word1: str, word2: str, wordlist: List[str]) -> List[str]:
+    """
+    Find the shortest word ladder between two input words.
+
+    Args:
+        word1: The first input word.
+        word2: The second input word.
+        wordlist: A list of words to search for the word ladder.
+
+    Returns:
+        A list of words in the ladder if it exists, otherwise an empty list.
+    """
+    # Check if input words are valid
+    wordlen = len(word1)
+    wordset = set(wordlist)
+    if word1 not in wordset or word2 not in wordset or len(word2) != wordlen:
+        return []
+
+    # Use breadth-first search to find shortest ladder
+    queue = [(word1, [word1])]
+    visited = set([word1])
+    while queue:
+        word, path = queue.pop(0)
+        for i in range(wordlen):
+            for char in "abcdefghijklmnopqrstuvwxyz":
+                newword = word[:i] + char + word[i + 1 :]
+                if newword == word2:
+                    return path + [word2]
+                if newword in wordset and newword not in visited:
+                    queue.append((newword, path + [newword]))
+                    visited.add(newword)
+
+    # If no ladder is found, return empty list
+    return []
+
+
+# Test cases
+wordlist = ["cold", "cord", "core", "care", "card", "ward", "warm", "worm"]
+
+# Test case 1: Find the shortest ladder from "cold" to "warm"
+ladder = find_shortest_ladder("cold", "warm", wordlist)
+assert ladder == ["cold", "cord", "card", "ward", "warm"], "Test case 1 failed"
diff --git a/challenge-008/lubos-kolouch/perl/ch-1.pl b/challenge-008/lubos-kolouch/perl/ch-1.pl
new file mode 100644
index 0000000000..e653bb41f7
--- /dev/null
+++ b/challenge-008/lubos-kolouch/perl/ch-1.pl
@@ -0,0 +1,32 @@
+use strict;
+use warnings;
+
+sub is_prime {
+    my $num = shift;
+    return 0 if ( $num < 2 );
+    for ( my $i = 2 ; $i <= sqrt($num) ; $i++ ) {
+        return 0 if ( $num % $i == 0 );
+    }
+    return 1;
+}
+
+sub get_next_prime {
+    my $num = shift;
+    $num++;
+    while ( !is_prime($num) ) {
+        $num++;
+    }
+    return $num;
+}
+
+my @perfect_numbers = ();
+my $p               = 2;
+my $num             = 2**( $p - 1 ) * ( 2**$p - 1 );
+while ( scalar(@perfect_numbers) < 5 ) {
+    push @perfect_numbers, $num;
+    $p   = get_next_prime($p);
+    $num = 2**( $p - 1 ) * ( 2**$p - 1 );
+}
+
+print "The first five perfect numbers are: ";
+print join( ", ", @perfect_numbers );
diff --git a/challenge-008/lubos-kolouch/perl/ch-2.pl b/challenge-008/lubos-kolouch/perl/ch-2.pl
new file mode 100644
index 0000000000..1d622194a6
--- /dev/null
+++ b/challenge-008/lubos-kolouch/perl/ch-2.pl
@@ -0,0 +1,24 @@
+sub center {
+    my @lines = @_;
+
+    # Find the maximum length of the lines
+    my $max_length = 0;
+    foreach my $line (@lines) {
+        my $length = length($line);
+        if ( $length > $max_length ) {
+            $max_length = $length;
+        }
+    }
+
+    # Center each line by adding spaces at the beginning
+    my @centered_lines;
+    foreach my $line (@lines) {
+        my $padding       = ( $max_length - length($line) ) / 2;
+        my $centered_line = ' ' x int($padding) . $line;
+        push @centered_lines, $centered_line;
+    }
+
+    return @centered_lines;
+}
+
+print( center( "This", "is", "a test of the", "center function" ) );
diff --git a/challenge-008/lubos-kolouch/python/ch-1.py b/challenge-008/lubos-kolouch/python/ch-1.py
new file mode 100644
index 0000000000..510cecef94
--- /dev/null
+++ b/challenge-008/lubos-kolouch/python/ch-1.py
@@ -0,0 +1,30 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+
+def is_prime(num: int) -> bool:
+    if num < 2:
+        return False
+    for i in range(2, int(num**0.5) + 1):
+        if num % i == 0:
+            return False
+    return True
+
+
+def get_next_prime(num: int) -> int:
+    num += 1
+    while not is_prime(num):
+        num += 1
+    return num
+
+
+perfect_numbers = []
+p = 2
+num = 2 ** (p - 1) * (2**p - 1)
+
+while len(perfect_numbers) < 5:
+    perfect_numbers.append(num)
+    p = get_next_prime(p)
+    num = 2 ** (p - 1) * (2**p - 1)
+
+print("The first five perfect numbers are:", perfect_numbers)
diff --git a/challenge-008/lubos-kolouch/python/ch-2.py b/challenge-008/lubos-kolouch/python/ch-2.py
new file mode 100644
index 0000000000..0b0c06baa3
--- /dev/null
+++ b/challenge-008/lubos-kolouch/python/ch-2.py
@@ -0,0 +1,24 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+from typing import List
+
+
+def center(lines: List[str]) -> List[str]:
+    # Find the maximum length of the lines
+    max_length = max(len(line) for line in lines)
+
+    # Center each line by adding spaces at the beginning
+    centered_lines = []
+    for line in lines:
+        padding = (max_length - len(line)) // 2
+        centered_line = " " * padding + line
+        centered_lines.append(centered_line)
+
+    return centered_lines
+
+
+# Test cases
+lines1 = ["This", "is", "a test of the", "center function"]
+expected1 = ["     This", "      is", " a test of the", "center function"]
+assert center(lines1) == expected1