RosettaCodeData/Task/Hamming-numbers/Go/hamming-numbers-1.go
Ingy döt Net db842d013d A-M baby
2013-04-10 21:29:02 -07:00

35 lines
828 B
Go

package main
import (
"fmt"
"math/big"
)
func min(a, b *big.Int) *big.Int {
if a.Cmp(b) < 0 {
return a
}
return b
}
func hamming(n int) []*big.Int {
h := make([]*big.Int, n)
h[0] = big.NewInt(1)
two, three, five := big.NewInt(2), big.NewInt(3), big.NewInt(5)
next2, next3, next5 := big.NewInt(2), big.NewInt(3), big.NewInt(5)
i, j, k := 0, 0, 0
for m := 1; m < len(h); m++ {
h[m] = new(big.Int).Set(min(next2, min(next3, next5)))
if h[m].Cmp(next2) == 0 { i++; next2.Mul( two, h[i]) }
if h[m].Cmp(next3) == 0 { j++; next3.Mul(three, h[j]) }
if h[m].Cmp(next5) == 0 { k++; next5.Mul( five, h[k]) }
}
return h
}
func main() {
h := hamming(1e6)
fmt.Println(h[:20])
fmt.Println(h[1691-1])
fmt.Println(h[len(h)-1])
}