クイックソート
sub quick_sort {
printf "DEBUG: %s\n", join( ',', @nums );
my ( $i, $j ) = @_;
my ( $left, $right ) = ( $i, $j );
my $pivot = int( ( $i + $j ) / 2 );
say "DEBUG: PV:$pivot LEFT:$i RIGHT:$j";
while ( $i < $j ) {
while ( $nums[$i] < $nums[$pivot] ) { $i++; }
while ( $nums[$j] > $nums[$pivot] ) { $j--; }
if ( $i < $j ) {
printf "DEBUG: SWAP: %d,%d\n", $nums[$i], $nums[$j];
my $temp = $nums[$i];
$nums[$i] = $nums[$j];
$nums[$j] = $temp;
}
}
if ( $left < $pivot - 1 ) {
quick_sort( $left, $pivot - 1 );
}
if ( $pivot + 1 < $right ) {
quick_sort( $pivot, $right );
}
}
quick_sort(0, $#nums);
say Dumper \@nums;
参考
