TWC333

Challenge Link

Task1

We check if the coordinates form a straight line:

#!/usr/bin/env perl
use strict;
use warnings;

sub straight_line{
  my ($m) = @_;
  my ($x1,$y1,$x2,$y2) = ($m->[0][0],$m->[0][1],$m->[1][0],$m->[1][1]);
  for(my $i = 2; $i < @$m; ++$i) {
    my ($x,$y) = ($m->[$i][0],$m->[$i][1]);
    return 0 if(($x - $x1) * ($y2 - $y1) != ($y - $y1) * ($x2 - $x1))
  }
  1
}

printf "%d\n",straight_line([[2,1],[2,3],[2,5]]);
printf "%d\n",straight_line([[1,4],[3,4],[10,4]]);
printf "%d\n",straight_line([[0,0],[1,1],[2,3]]);
printf "%d\n",straight_line([[1,1],[1,1],[1,1]]);
printf "%d\n",straight_line([[1000000,1000000],
			     [2000000,2000000],
			     [3000000,3000000]]);

Task2

We duplicate each zero twice until we reach array size and stop:

#!/usr/bin/env perl
use strict;
use warnings;
use Data::Show;

sub duplicate_zeros{
  my ($arr) = @_;
  my ($i,@stk) = (0);
  while($i < @$arr && @stk != @$arr){
    if($arr->[$i] == 0 && (@stk+1 < @$arr)) {
      push @stk,0 for 0..1;
      $i++
    } else {
      push @stk,$arr->[$i++]
    }
  }
  @stk
}

print show duplicate_zeros([1,0,2,3,0,4,5,0]);
print show duplicate_zeros([1,2,3]);
print show duplicate_zeros([1,2,3,0]);
print show duplicate_zeros([0,0,1,2]);
print show duplicate_zeros([1,2,0,3,4]);