diff options
| -rw-r--r-- | challenge-097/james-smith/perl/ch-2.pl | 69 |
1 files changed, 44 insertions, 25 deletions
diff --git a/challenge-097/james-smith/perl/ch-2.pl b/challenge-097/james-smith/perl/ch-2.pl index d84ab14199..be87aefd86 100644 --- a/challenge-097/james-smith/perl/ch-2.pl +++ b/challenge-097/james-smith/perl/ch-2.pl @@ -13,6 +13,27 @@ is( min_flips('101100100100101',3), 2 ); is( min_flips('101101',3), 0 ); is( min_flips('0000000100100011010001010110011110001001101010111100110111101111',4), 32 ); +is( mf_1('101100101',3), 1 ); +is( mf_1('10110111', 4), 2 ); +is( mf_1('100101100',3), 1 ); +is( mf_1('101100100100101',3), 2 ); +is( mf_1('101101',3), 0 ); +is( mf_1('0000000100100011010001010110011110001001101010111100110111101111',4), 32 ); + +is( mf_2('101100101',3), 1 ); +is( mf_2('10110111', 4), 2 ); +is( mf_2('100101100',3), 1 ); +is( mf_2('101100100100101',3), 2 ); +is( mf_2('101101',3), 0 ); +is( mf_2('0000000100100011010001010110011110001001101010111100110111101111',4), 32 ); + +is( min_flips_more_readable('101100101',3), 1 ); +is( min_flips_more_readable('10110111', 4), 2 ); +is( min_flips_more_readable('100101100',3), 1 ); +is( min_flips_more_readable('101100100100101',3), 2 ); +is( min_flips_more_readable('101101',3), 0 ); +is( min_flips_more_readable('0000000100100011010001010110011110001001101010111100110111101111',4), 32 ); + done_testing(); ## As the first problem was a good one for applying "Golfing" @@ -57,7 +78,7 @@ done_testing(); ## locations ($_ is the value of the element of variable that ## the map function is processing ## -## * map { [ $_, substr$_[0],$_,$_[1] ] } - this grabs the +## * map { substr$_[0],$_,$_[1] } - this grabs the ## substring for the nth block - but keeps the start location ## as we will need it later... Here we see a map returning an ## arrayref - in subsequent requests - $_->[0] is the start @@ -67,11 +88,11 @@ done_testing(); ## You have to be careful here as $_[0] and $_->[0] look similar ## but are different ## -## * map { [ $_->[0], $_->[1] x $\ ] } - this maps the string we +## * map { $_ x $\ } - this maps the string we ## just have to have the same length as our original string - ## by performing a perl "string multiplication" x ## -## * map { [ $_->[0], ( $_[0] ^ $_->[1] ) =~ y/\1/\1/ ] } - +## * map { ( $_[0] ^ $_ ) =~ y/\1/\1/ } - ## count the flips. Two perlisms here - we can use xor operator ## ^ on strings to xor the binary values of each string. ## y/../../ - the translate operator returns the number of @@ -81,7 +102,7 @@ done_testing(); ## a character "\0" and when they are different the value is 1 ## or as a characther "\1" ## -## * map { $/ = !$_->[0] || $_->[1] < $/ ? $_->[1] : $/ } - finally +## * map { $/ = $_ < $/ ? $_ : $/ } - finally ## we keep the running total of the minimum value - Now this is ## why we kept the start of the block around - as the first ## time through the loop we have to define the minimum - if @@ -100,37 +121,35 @@ done_testing(); sub min_flips { ## Golf mode on... [ - local$/, - local$\=length($_[0])/$_[1], - map{$/=!$_->[0]||$_->[1]<$/?$_->[1]:$/} - map{[$_->[0],($_[0]^$_->[1])=~y/\1/\1/]} - map{[$_->[0],$_->[1]x$\]} - map{[$_,substr$_[0],$_,$_[1]]} + local$/=length$_[0], + local$\=$//$_[1], + map{$/=$_<$/?$_:$/} + map{($_[0]^$_)=~y/\1/\1/} + map{$_ x$\} + map{substr$_[0],$_,$_[1]} map{$_*$_[1]} 0..$\-1 ]->[-1] } -## Now as a one liner [all 213 cha.... +sub mf_1{[local$/=length$_[0],local$\=$//$_[1],map{$/=$_<$/?$_:$/}map{($_[0]^$_)=~y/\1/\1/}map{$_ x$\}map{substr$_[0],$_,$_[1]}map{$_*$_[1]}0..$\-1]->[-1]} -sub mf_1{[local$/,local$\=length($_[0])/$_[1],map{$/=!$_->[0]||$_->[1]<$/?$_->[1]:$/}map{[$_->[0],($_[0]^$_->[1])=~y/\1/\1/]}map{[$_->[0],$_->[1]x$\]}map{[$_,substr$_[0],$_,$_[1]]}map{$_*$_[1]}0..$\-1]->[-1]} +## Now as a one liner [all 155 characters] - 145 inside the curly braces.. -sub mf_1wrap{[local$/,local$\=length($_[0])/$_[1],map{$/=!$_->[0]||$_-> -[1]<$/?$_->[1]:$/}map{[$_->[0],($_[0]^$_->[1])=~y/\1/\1/]}map{[$_->[0], -$_->[1]x$\]}map{[$_,substr$_[0],$_,$_[1]]}map{$_*$_[1]}0..$\-1]->[-1]} +sub mf_2{[local$/=length$_[0],local$\=$//$_[1],map{$/=$_<$/?$_:$/}map{($_[0]^$_) +=~y/\1/\1/}map{$_ x$\}map{substr$_[0],$_,$_[1]}map{$_*$_[1]}0..$\-1]->[-1]} ## With the white space back in.. sub min_flips_more_readable { return [ - local $/, # Accumulator for min value - local $\ = length($_[0]) / $_[1], # No of blocks - - map { $/ = !$_->[0] || $_->[1] < $/ ? $_->[1] : $/ } # Update min if first block OR value < min - map { [ $_->[0], ( $_[0] ^ $_->[1] ) =~ y/\1/\1/ ] } # Get number of flipped letters - map { [ $_->[0], $_->[1] x $\ ] } # Repeat sub-block so same length as string - map { [ $_, substr $_[0], $_, $_[1] ] } # Get "nth" sub-block - map { $_ * $_[1] } # Convert index to start location - 0 .. $\ - 1 # Block indexes... - ]->[ -1 ]; # Get last value from list {minimum} + local $/ = length($_[0]), # Minimum value (bounded above by length) + local $\ = $/ / $_[1], # No of blocks + map { $/ = $_ < $/ ? $_ : $/ } # Update min if first block OR value < min + map { ( $_[0] ^ $_ ) =~ y/\1/\1/ } # Get number of flipped letters + map { $_ x $\ } # Repeat sub-block so same length as string + map { substr $_[0], $_, $_[1] } # Get "nth" sub-block + map { $_ * $_[1] } # Convert index to start location + 0 .. $\ - 1 # Block indexes... + ]->[ -1 ]; # Get last value from list {minimum} } |