use sort '';

print sort::current;
mergesort

@array = 1..99;

$c=0; @b = sort{ $c++; $a <=> $b } @array, 0; print $c
113;

$c=0; @b = sort{ $c++; $a <=> $b } @array, 100; print $c
99;

$c=0; @b = sort{ $c++; $a <=> $b } @array, 50; print $c
127

$c=0; @b = sort{ $c++; $a <=> $b } @array, 49; print $c
127

$c=0; @b = sort{ $c++; $a <=> $b } @array, 75; print $c
127

$c=0; @b = sort{ $c++; $a <=> $b } @array, 12; print $c
122