明解Ｃ言語 入門編 > 10. ポインタ > ２つの値を交換する Perl sub swap1 { my ($nx, $ny) = @_; my $tmp = $nx; $nx = $ny; $ny = $tmp; } sub swap2 { my ($nx, $ny) = @_; my $tmp = $$nx; $$nx = $$ny; $$ny = $tmp; } $na = 57; $nb = 21; printf("整数…