package collatz import ( "collatz/io" "fmt" "log" "math/big" ) type Calculator struct { parser *io.Cliargs three *big.Int two *big.Int one *big.Int } func NewCalculator(parser *io.Cliargs) Calculator { r := Calculator{ parser: parser, three: new(big.Int).SetInt64(3), two: new(big.Int).SetInt64(2), one: new(big.Int).SetInt64(1), } return r } func (o Calculator) Collatz() { err := o.parser.Parse() if err != nil { log.Panicf("Couldn't parse input: %s\n", err) } number := o.parser.GetNumber() fmt.Print(number.Text(10)) o.nextNumber(number) fmt.Println() } func (o Calculator) nextNumber(in *big.Int) { if in.Cmp(o.one) < 0 { log.Panicln("Must be greater than 0") } if in.Cmp(o.one) == 0 { return } var newNumber *big.Int if new(big.Int).And(in, o.one).Cmp(o.one) == 0 { newNumber = new(big.Int).Add(new(big.Int).Mul(in, o.three), o.one) } else { newNumber = new(big.Int).Div(in, o.two) } fmt.Printf(" -> %s", newNumber.Text(10)) o.nextNumber(newNumber) }