9.4.1.2. Warunek pętli
for (int j = len-2;j >= 0;j--){
carry = (digits[j]+carry)/10 ;
digits[j] =(digits[j]+carry)%10 ;
}
Outstanding Ox
for (int j = len-2;j >= 0;j--){
carry = (digits[j]+carry)/10 ;
digits[j] =(digits[j]+carry)%10 ;
}