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ch-2.pl
executable file
·60 lines (38 loc) · 951 Bytes
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ch-2.pl
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#!/usr/bin/perl -s
use v5.24;
use Test2::V0;
use List::Util 'sum0';
our ($tests, $examples, $bits);
run_tests() if $tests || $examples; # does not return
die <<EOS unless defined $bits and @ARGV;
usage: $0 [-examples] [-tests] [-bits=K] [N...]
-examples
run the examples from the challenge
-tests
run some tests
-bits=K
sum over numbers with a k-bit index
N...
list of numbers
EOS
### Input and Output
say k_bit_sum($bits, @ARGV);
### Implementation
sub k_bit_sum {
my $k = shift;
sum0 @_[grep unpack('%32b*', pack('l', $_)) == $k, 0 .. $#_];
}
### Examples and tests
sub run_tests {
SKIP: {
skip "examples" unless $examples;
is k_bit_sum(1 ,=> 2, 5, 9, 11, 3), 17, 'example 1';
is k_bit_sum(2 ,=> 2, 5, 9, 11, 3), 11, 'example 2';
is k_bit_sum(0 ,=> 2, 5, 9, 11, 3), 2, 'example 3';
}
SKIP: {
skip "tests" unless $tests;
}
done_testing;
exit;
}