sequence can have more methods with it, we can find first five values of
a sequence.
but we don't do this with a generator
struct Fibonacci: SequenceType {
var first, second: Int
func generate() -> AnyGenerator<Int> {
var a = first
var b = second
return anyGenerator {
let temp = a
(a, b) = (b, a + b)
return temp
}
}
}
Array(Fibonacci(first: 1, second: 1).prefix(10))
Happy new year to all
2015-12-31 21:57 GMT+08:00 Dmitri Gribenko <[email protected]>:
> On Thu, Dec 31, 2015 at 3:36 PM, Susan Cheng <[email protected]>
> wrote:
> > I don't think so.
> >
> > As we don't say "Fibonacci collection", we know Fibonacci numbers are in
> > order. But we can't tell the number immediately if I asked a specific
> index
> > of Fibonacci sequence. The only way is calculate the sequence one by one
> > from start.
>
> That's OK, collections can have Forward indices which have exactly
> these properties.
>
> Dmitri
>
> --
> main(i,j){for(i=2;;i++){for(j=2;j<i;j++){if(!(i%j)){j=0;break;}}if
> (j){printf("%d\n",i);}}} /*Dmitri Gribenko <[email protected]>*/
>
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