Distinct palindromes within decimal numbers: Difference between revisions

=={{header|Raku}}==

A minor modification of the [[Longest_palindromic_substrings#Raku|Longest palindromic substrings]] task. As such, works for any string, not just integers.

<lang perl6>use Sort::Naturally;

sub getpal ($str) {

my @chars = $str.comb;

my @pal = flat @chars,

(1 ..^ @chars).map: -> \idx {

my @s;

for 1, 2 {

my int ($rev, $fwd) = $_, 1;

loop {

quietly last if ($rev > idx) || (@chars[idx - $rev] ne @chars[idx + $fwd]);

$rev = $rev + 1;

$fwd = $fwd + 1;

}

@s.push: @chars[idx - $rev ^..^ idx + $fwd].join if $rev + $fwd > 2;

last if @chars[idx - 1] ne @chars[idx];

}

next unless +@s;

@s

}

@pal.unique.sort({.chars, &naturally});

}

say 'All palindromic substrings including (bizarrely enough) single characters:';

put "$_ => ", getpal $_ for 100..125;

put "\nDo these strings contain a minimum two character palindrome?";

printf "%25s => %s\n", $_, getpal($_).tail.chars > 1 for flat

9, 169, 12769, 1238769, 123498769, 12346098769, 1234572098769,

123456832098769, 12345679432098769, 1234567905432098769,

123456790165432098769, 83071934127905179083, 1320267947849490361205695,

<Do these strings contain a minimum two character palindrome?></lang>

{{out}}

<pre>All palindromic substrings including (bizarrely enough) single characters:

100 => 1 0 00

101 => 1 0 101

102 => 1 0 2

103 => 1 0 3

104 => 1 0 4

105 => 1 0 5

106 => 1 0 6

107 => 1 0 7

108 => 1 0 8

109 => 1 0 9

110 => 1 0 11

111 => 1 11 111

112 => 1 2 11

113 => 1 3 11

114 => 1 4 11

115 => 1 5 11

116 => 1 6 11

117 => 1 7 11

118 => 1 8 11

119 => 1 9 11

120 => 1 2 0

121 => 1 2 121

122 => 1 2 22

123 => 1 2 3

124 => 1 2 4

125 => 1 2 5

Do these strings contain a minimum two character palindrome?

9 => False

169 => False

12769 => False

1238769 => False

123498769 => False

12346098769 => False

1234572098769 => False

123456832098769 => False

12345679432098769 => False

1234567905432098769 => False

123456790165432098769 => False

83071934127905179083 => False

1320267947849490361205695 => True

Do => False

these => True

strings => False

contain => False

a => False

minimum => True

two => False

character => True

palindrome? => False</pre>