diff options
| -rw-r--r-- | challenge-047/duncan-c-white/README | 58 | ||||
| -rw-r--r-- | challenge-047/duncan-c-white/perl/Roman.pm | 108 | ||||
| -rwxr-xr-x | challenge-047/duncan-c-white/perl/ch-1.pl | 54 | ||||
| -rwxr-xr-x | challenge-047/duncan-c-white/perl/ch-2.pl | 41 |
4 files changed, 220 insertions, 41 deletions
diff --git a/challenge-047/duncan-c-white/README b/challenge-047/duncan-c-white/README index 8a4cac1fc2..3321e4e769 100644 --- a/challenge-047/duncan-c-white/README +++ b/challenge-047/duncan-c-white/README @@ -1,52 +1,28 @@ -Task 1: "Cryptic Message: +Task 1: "Roman Calculator -The communication system of an office is broken and messages received -are not completely reliable. To send the message Hello 6 times, it ended -up sending these following: +Write a script that accepts two roman numbers and operation. It should +then perform the operation on the give roman numbers and print the result. -H x l 4 ! -c e - l o -z e 6 l g -H W l v R -q 9 m # o +For example, -Similarly another day we received a message repeatedly like below: +perl ch-1.pl V + VI -P + 2 l ! a t o -1 e 8 0 R $ 4 u -5 - r ] + a > / -P x w l b 3 k \ -2 e 3 5 R 8 y u -< ! r ^ ( ) k 0 +should print -Write a script to decrypt the above repeated message (one message repeated -6 times). - -HINT: Look for characters repeated in a particular position in all six -messages received. +XI " -My notes: ah, so pick maxfreq letter in each column? - -Task #2: "Is the room open? +My notes: cute, especially given that we did Roman->Int and Int->Roman in challenge 10:-). +So convert Roman->Int, Do Op, Int->Roman for the result. Added the ability for the user +to specify the operands in EITHER Roman or Arabic. -There are 500 rooms in a hotel with 500 employees having keys to all the -rooms. The first employee opened main entrance door of all the rooms. The -second employee then closed the doors of room numbers 2,4,6,8,10 and -so on to 500. The third employee then closed the door if it was opened -or opened the door if it was closed of rooms 3,6,9,12,15 and so on to -500. Similarly the fourth employee did the same as the third but only -room numbers 4,8,12,16 and so on to 500. This goes on until all employees -has had a turn. +Task #2: "Gapful Numbers -Write a script to find out all the rooms still open at the end. +Write a script to print first 20 Gapful Numbers greater than or equal +to 100. See https://oeis.org/A108343 for details. +In summary, Gapful Numbers are those numbers >= 100 that are divisible +by the number formed by their first and last digit. Numbers up to 100 +trivially have this property and are excluded. eg. 100 is, because 100%10==0 " -My notes: sounds pretty easy, two nested for loops, but one of those questions -where I can't predict in advance what the answer will be. - -But having written the naive roomopen[r] based solution, I find that the -answer is: the open rooms are all the room numbers that are exact squares! -I'm not sure why, but I then implemented that more directly, with no -arrays. I then translated that into Postscript too, see the postscript -directory:-) +My notes: cute. Sounds easy. diff --git a/challenge-047/duncan-c-white/perl/Roman.pm b/challenge-047/duncan-c-white/perl/Roman.pm new file mode 100644 index 0000000000..ea7d572ffc --- /dev/null +++ b/challenge-047/duncan-c-white/perl/Roman.pm @@ -0,0 +1,108 @@ +# Back in Challenge 10, task 1 "Write a script to encode/decode Roman numerals. +# For example, given Roman numeral CCXLVI, it should return 246. +# Similarly, for decimal number 39, it should return XXXIX." +# These are my routines toroman(n) and fromroman(r), converted into a module. + + +use strict; +use warnings; +use feature 'say'; +use Function::Parameters; +use Test::More; +#use Data::Dumper; + + +# +# my $roman = oneroman( $digit, $one, $five, $ten ); +# Given a single $digit (0..9), build and return +# the roman-numeral equivalent, using $one, $five and $ten, +# the roman-numeral equivalents of 1, 5 and 10. If those were +# 'I', 'V' and 'X', the roman-numerals equivalents of each digit +# are '', I, II, III, IV, V, VI, VII, VIII, IX +# +fun oneroman( $digit, $one, $five, $ten ) +{ + return $one x $digit if $digit<4; # 0..3 + return "$one$five" if $digit==4; # 4 + return $five.($one x ($digit-5)) if $digit<9; # 5..9 + return "$one$ten"; # 9 +} + + +# +# my $roman = toroman( $n ); +# Given $n, a positive integer from 1..3999, +# convert it to a roman-numeral string, eg 246 => CCXLVI +# +fun toroman( $n ) +{ + die "toroman: $n should be 1..3999\n" if $n<1 || $n>3999; + + my $roman = ''; + + # deal with the thousands.. + my $m = int($n/1000); + $roman = ( 'M' x $m ); + $n %= 1000; + + # deal with the hundreds.. + $roman .= oneroman( int($n/100), 'C', 'D', 'M' ); + $n %= 100; + + # deal with the tens.. + $roman .= oneroman( int($n/10), 'X', 'L', 'C' ); + $n %= 10; + + # deal with the ones.. + $roman .= oneroman( $n, 'I', 'V', 'X' ); + + return $roman; +} + + + +# +# my $n = fromroman( $roman ); +# Given $roman, a well-formed roman-numeral string, +# convert it to an integer. +# +fun fromroman( $roman ) +{ + my $orig = $roman; + my $result = 0; + $result += 1000 while $roman =~ s/^M//; + $result += 900 if $roman =~ s/^CM//; + $result += 500 if $roman =~ s/^D//; + $result += 400 if $roman =~ s/^CD//; + $result += 100 while $roman =~ s/^C//; + $result += 90 if $roman =~ s/^XC//; + $result += 50 if $roman =~ s/^L//; + $result += 40 if $roman =~ s/^XL//; + $result += 10 while $roman =~ s/^X//; + $result += 9 if $roman =~ s/^IX//; + $result += 5 if $roman =~ s/^V//; + $result += 4 if $roman =~ s/^IV//; + $result += 1 while $roman =~ s/^I//; + die "fromroman: roman '$orig' not empty at end, $roman left over\n" + if $roman; + return $result; +} + +# testroman(): +# +fun testroman() +{ + # check toroman() and fromroman() work: try converting every number to roman, + # and then back again, checking that you end up with... + # i.e "the number you first thought of":-). + foreach my $n (1..3999) + { + my $roman = toroman( $n ); + my $n2 = fromroman( $roman ); + is( $n, $n2, "fromroman(toroman($n))==$n" ); + } + done_testing(); +} + + +1; diff --git a/challenge-047/duncan-c-white/perl/ch-1.pl b/challenge-047/duncan-c-white/perl/ch-1.pl new file mode 100755 index 0000000000..593f0df701 --- /dev/null +++ b/challenge-047/duncan-c-white/perl/ch-1.pl @@ -0,0 +1,54 @@ +#!/usr/bin/perl +# +# +# Task 1: "Roman Calculator +# +# Write a script that accepts two roman numbers and operation. It should +# then perform the operation on the give roman numbers and print the result. +# +# For example, +# +# perl ch-1.pl V + VI +# +# should print +# +# XI +# " +# +# My notes: cute, especially given that we did Roman->Int and Int->Roman in challenge 10:-). +# So convert Roman->Int, Do Op, Int->Roman for the result. +# + +use feature 'say'; +use strict; +use warnings; +use Data::Dumper; + +use lib qw(.); +use Roman; + +die "Usage: romancalc R1 OP R2 [R1 and R2 are Roman numerals or integers]\n". + "or: romancalc test\n" + unless @ARGV==3 || (@ARGV==1 && $ARGV[0] eq "test"); + +if( @ARGV==1 && $ARGV[0] eq "test" ) +{ + testroman(); + exit 0; +} + +my( $r1, $op, $r2 ) = @ARGV; +my $origr1 = $r1; +my $origr2 = $r2; + +$r1 = fromroman($r1) if $r1 =~ /^[MCDLXVI]+$/; +$r2 = fromroman($r2) if $r2 =~ /^[MCDLXVI]+$/; + +die "romancalc: bad r1: $r1\n" unless $r1 > 1 && $r1 < 4000; +die "romancalc: bad r2: $r2\n" unless $r2 > 1 && $r2 < 4000; + +my $n = eval "$r1 $op $r2" || die "romancalc: bad operator $op\n"; +$n = int($n); + +my $r = toroman($n); +say "result of $origr1 ($r1) $op $origr2 ($r2): $r ($n)"; diff --git a/challenge-047/duncan-c-white/perl/ch-2.pl b/challenge-047/duncan-c-white/perl/ch-2.pl new file mode 100755 index 0000000000..c894655165 --- /dev/null +++ b/challenge-047/duncan-c-white/perl/ch-2.pl @@ -0,0 +1,41 @@ +#!/usr/bin/perl +# +# Task #2: "Gapful Numbers +# +# Write a script to print first 20 Gapful Numbers greater than or equal +# to 100. See https://oeis.org/A108343 for details. +# In summary, Gapful Numbers are those numbers >= 100 that are divisible +# by the number formed by their first and last digit. Numbers up to 100 +# trivially have this property and are excluded. eg. 100 is, because 100%10==0 +# " +# +# My notes: cute. Sounds easy. +# + +use feature 'say'; +use strict; +use warnings; +use Function::Parameters; + +# +# gapful( $i ); +# Return 1 iff $i is a gapful number >= 100. +# +fun gapful( $i ) +{ + $i =~ /^(\d).*(\d)$/; # find first and largest digits + my $div = 10*$1 + $2; + return $i % $div == 0 ? 1 : 0; +} + + +die "Usage: ch-2.pl [FirstN]\n" if @ARGV>1; +my $n = shift // 20; + +my $found = 0; +for( my $i = 100; $found<$n; $i++ ) +{ + next unless gapful( $i ); + say $i; + $found++; +} |