Merge pull request #3056 from pauloscustodio/085-perl

Add Perl solution to challenge 085

4 files changed, 149 insertions, 0 deletions

diff --git a/challenge-085/paulo-custodio/README b/challenge-085/paulo-custodio/README
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+++ b/challenge-085/paulo-custodio/README
@@ -0,0 +1 @@
+Solution by Paulo Custodio
diff --git a/challenge-085/paulo-custodio/perl/ch-1.pl b/challenge-085/paulo-custodio/perl/ch-1.pl
new file mode 100644
index 0000000000..0d99e7ebd6
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+++ b/challenge-085/paulo-custodio/perl/ch-1.pl
@@ -0,0 +1,63 @@
+#!/usr/bin/env perl
+
+# Challenge 085
+#
+# TASK #1 › Triplet Sum
+# Submitted by: Mohammad S Anwar
+# You are given an array of real numbers greater than zero.
+# 
+# Write a script to find if there exists a triplet (a,b,c) such that 1 < a+b+c < 2. Print 1 if you succeed otherwise 0.
+# 
+# Example 1:
+# Input: @R = (1.2, 0.4, 0.1, 2.5)
+# Output: 1 as 1 < 1.2 + 0.4 + 0.1 < 2
+# Example 2:
+# Input: @R = (0.2, 1.5, 0.9, 1.1)
+# Output: 0
+# Example 3:
+# Input: @R = (0.5, 1.1, 0.3, 0.7)
+# Output: 1 as 1 < 0.5 + 1.1 + 0.3 < 2
+
+use strict;
+use warnings;
+use 5.030;
+
+my @R = @ARGV;
+@R >= 3 or die "Need at least 3 values\n";
+
+say found(@R);
+
+# check sum of a triplet
+sub check {
+	my($result, $a, $b, $c) = @_;
+	my $sum = $a + $b + $c;
+	if (1 < $sum && $sum < 2) {
+		$$result = 1;
+	}
+}
+
+# next combination
+sub next_combination {
+	my($result, $set, $comb, $k) = @_;
+	if ($$result) {					# trim tree, already found a solution
+		return;	
+	}
+	elsif ($k == 0) {				# check one triplet
+		check($result, @$comb);
+	}
+	else {							# compute next combination
+		my @comb = @$comb;
+		for my $i (scalar(@comb) .. scalar(@$set)-$k) {
+			push @comb, $set->[$i];
+			next_combination($result, $set, \@comb, $k-1);
+			pop @comb;
+		}
+	}
+}
+
+sub found {
+	my(@set) = @_;
+	my $result = 0;
+	next_combination(\$result, \@set, [], 3);		# check triplets
+	return $result;
+}
diff --git a/challenge-085/paulo-custodio/perl/ch-2.pl b/challenge-085/paulo-custodio/perl/ch-2.pl
new file mode 100644
index 0000000000..a0fd2373bf
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+++ b/challenge-085/paulo-custodio/perl/ch-2.pl
@@ -0,0 +1,62 @@
+#!/usr/bin/env perl
+
+# Challenge 085
+#
+# TASK #2 › Power of Two Integers
+# Submitted by: Mohammad S Anwar
+# You are given a positive integer $N.
+# 
+# Write a script to find if it can be expressed as a ** b where a > 0 and b > 1. Print 1 if you succeed otherwise 0.
+# 
+# Example 1:
+# Input: 8
+# Output: 1 as 8 = 2 ** 3
+# Example 2:
+# Input: 15
+# Output: 0
+# Example 3:
+# Input: 125
+# Output: 1 as 125 = 5 ** 3
+
+use strict;
+use warnings;
+use 5.030;
+
+# Sieve of Eratosthenes
+my @sieve;
+my @primes;
+
+my($n) = @ARGV;
+say is_perfect_power($n);
+
+
+sub is_perfect_power {
+	my($n) = @_;
+	my $max_factor = sqrt($n)+1;
+	find_primes($max_factor);		# fill list of prime numbers up to sqrt(n)+1
+	for my $prime (@primes) {
+		my $exp = 1;
+		my $power;
+		while (($power = $prime ** $exp) <= $n) {
+			if ($power == $n) {
+				return 1;
+			}
+			$exp++;
+		}
+	}
+	return 0;
+}
+
+sub find_primes {
+	my($max) = @_;
+	my $prime = 2;
+	do {
+		push @primes, $prime;
+		for (my $f = $prime*2; $f < $max; $f += $prime) {
+			$sieve[$f] = 1;
+		}
+		do {
+			$prime++
+		} while ($prime < $max && $sieve[$prime]);
+	} while ($prime < $max);
+}
diff --git a/challenge-085/paulo-custodio/test.pl b/challenge-085/paulo-custodio/test.pl
new file mode 100644
index 0000000000..125b8798e9
--- /dev/null
+++ b/challenge-085/paulo-custodio/test.pl
@@ -0,0 +1,23 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use Test::More;
+use 5.030;
+
+is capture("perl/ch-1.pl 1.2 0.4 0.1 2.5"), "1\n";
+is capture("perl/ch-1.pl 0.2 1.5 0.9 1.1"), "0\n";
+is capture("perl/ch-1.pl 0.5 1.1 0.3 0.7"), "1\n";
+
+is capture("perl/ch-2.pl   8"), "1\n";
+is capture("perl/ch-2.pl  15"), "0\n";
+is capture("perl/ch-2.pl 125"), "1\n";
+
+done_testing;
+
+sub capture {
+	my($cmd) = @_;
+	my $out = `$cmd`;
+	$out =~ s/[ \t\v\f\r]*\n/\n/g;
+	return $out;
+}
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