use integer;

my @uha = qw(1 2 3 4 2 4 6 0 12); # Uint8 Array

say normalChecksum(@uha, scalar @uha); # 33
say simpleChecksum(@uha);              # 33

# von c nach Perl
sub normalChecksum{
    my $n = pop @_;
    my ($i,$a,$bb);
    for($i = 1, $a = 0; $i < $n; $i++){
        $a += $_[$i];
    }
    
    $bb = $a / 255;
    $a = ($a - 256 * $bb) + $bb;
    $bb = $a / 256;

    return ($a-256*$bb) + $bb;
}

# Vereinfachung mit pack
sub simpleChecksum{
    my @uha = @_;
    return unpack("%C*", pack "C*", @uha) - 1;
}

#include <stdio.h>

// 1 2 3 4 2 4 6 0 12

int main(void){
    int b[] = {1, 2, 3, 4, 2, 4, 6, 0, 12};
    printf("%u\n", normalChecksum(b, 9));
    return 0;
}


int normalChecksum(int *b, int n){
  int i;
  int a, bb;

  for(i = 1, a = 0; i < n; i++)
    a+=(int)b[i];

  bb = a / 256;
  a = (a - 256 * bb) + bb;
  bb = a / 256;

  return (int)((a-256*bb)+bb);
}