ch-2.pl

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diff --git a/challenge-039/ndelucca/perl5/ch-2.pl b/challenge-039/ndelucca/perl5/ch-2.pl
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+#!/usr/bin/perl
+
+# https://perlweeklychallenge.org/blog/perl-weekly-challenge-039/
+# Task #2
+# Write a script to demonstrate Reverse Polish notation(RPN).
+# Checkout the wiki page for more information about RPN.
+# https://en.wikipedia.org/wiki/Reverse_Polish_notation
+
+use strict;
+use warnings;
+
+die "Input required" unless @ARGV;
+
+my @stack;
+my @rpn = split / /, shift;
+
+while (@rpn) {
+
+    my $in = shift @rpn;
+
+    if ($in =~ /^\d+$/) {
+        push @stack, $in;
+    }else{
+        my $num1 = pop @stack;
+        my $num2 = pop @stack;
+        push @stack, eval "$num2 $in $num1";
+    }
+}
+
+print "Result: ",@stack, "\n";