The Weekly Challenge - 262


TASK #1: Max Positive Negative
You are given an array of integers, @ints. Write a script to return the maximum number of either positive or negative integers in the given array.

Here my solution, without keyword 'my', without validating '@ints', without a module:


sub max_pos_neg {
   ( ($pos = scalar(grep { $_ > 0 } @_)) > ($neg = scalar(grep { $_ < 0} @_)) ) ? print("max positive integers: $pos\n") : print("max negative integers: $neg\n");
}

#assumption 1: no number 0
#assumption 2: number of positive and negative integers differ

@ints = qw(-3 1 2 -1 3 -2 4);
max_pos_neg(@ints); # max positive integers: 4

@ints = qw(-1 -2 -3 1);
max_pos_neg(@ints); # max negative integers: 3

@ints = qw(1 2);
max_pos_neg(@ints); # max positive integers: 2
Alternative:

assumption 1: no number 0
assumption 2: number of positive and negative integers differ, meaning
  - positive integers > negative integers: more than (scalar(@_)/2) is positive
  - negative integers > positive integers: less than (scalar(@_)/2) is positive


sub max_pos_neg {
   ( ($pos = scalar(grep { $_ > 0 } @_)) > (scalar(@_)/2) ) ? print("max positive integers: $pos\n") : print("max negative integers: ", (scalar(@_) - $pos) , "\n");
}

TASK #2: Count Equal Divisible
You are given an array of integers, @ints and an integer $k. Write a script to return the number of pairs (i, j) where

a) 0 <= i < j < size of @ints
b) ints[i] == ints[j]
c) i x j is divisible by k

Here my solution, without keyword 'my', without validating '@ints' and $k, without a module:

sub count_equal_divisible {
  ($aref, $k) = @_;	
  @array = @{$aref};
  $success = 0;

  for ($i = 0; $i < scalar(@array)-1; $i++) {
    for ($j = $i + 1; $j < scalar(@array); $j++) {
        $success++ if ( $array[$i] == $array[$j] && (($i * $j) % $k == 0) );
    }
  }
  print("The number of equal divisible pairs (i, j): ", $success, "\n");
}

@ints = qw(3 1 2 2 2 1 3); 
$k = 2;
count_equal_divisible(\@ints, $k); # 4

@ints = qw(1 2 3);
$k = 1;
count_equal_divisible(\@ints, $k); # 0