func main() {
var maxv = uint(65536)
args := os.Args[1:len(os.Args)]
log.Println("args", args)
if len(args) != 0 {
if _, err := os.Stat(args[0]); err == nil {
dumpfile(args[0])
return
}
maxv64, _ := strconv.ParseUint(args[0], 0, 64)
maxv = uint(maxv64)
}
var maxvv = uint(math.Sqrt(float64(maxv)))
log.Println("calculate primes", maxv, maxvv)
var bs = bitset.New(maxv)
for x := uint(1); x < maxvv; x++ {
for y := uint(1); y < maxvv; y++ {
var k = uint(4*x*x + y*y)
if k < maxv && (k%12 == 1 || k%12 == 5) {
bs.Flip(k)
}
k = uint(3*x*x + y*y)
if k < maxv && (k%12 == 7) {
bs.Flip(k)
}
if x > y {
k = 3*x*x - y*y
if k < maxv && k%12 == 11 {
bs.Flip(k)
}
}
}
}
cnt := bs.Count()
log.Println("bs.Count=", cnt, "/", bs.Len(), bs.Len()/(bs.Len()-cnt))
bs.Set(2)
bs.Set(3)
for n := uint(5); n < maxvv; n++ {
if bs.Test(n) {
n2 := n * n
for k := n2; k < maxv; k += n2 {
bs.Clear(k)
}
}
}
fp, err := os.Create("prime.dat")
if err != nil {
log.Panic("file open error")
}
defer fp.Close()
var primes = intseq.NewIntSeq()
for n := uint(2); n < maxv; n++ {
if bs.Test(n) {
primes.Add(uint64(n))
}
}
primes.Write(fp)
}
func dumpfile(fn string) {
var primes = intseq.NewIntSeq()
fp, err := os.Open(fn)
if err != nil {
log.Panic("open failed", err)
}
primes.Read(fp)
log.Println(primes)
}
func main() {
var maxv = uint(65536)
args := os.Args[1:len(os.Args)]
log.Println("args", args)
if len(args) != 0 {
if _, err := os.Stat(args[0]); err == nil {
dumpfile(args[0])
return
}
maxv64, _ := strconv.ParseUint(args[0], 0, 64)
maxv = uint(maxv64)
}
var maxvv = uint((maxv-2-1)/2 + 1)
log.Println("calculate primes", maxv, maxvv)
// var maxv uint = 65536
var bs = bitset.New(maxvv)
for j := uint(1); j < maxvv; j++ {
for i := uint(1); i <= j; i++ {
if i+j+2*i*j > maxvv {
break
}
bs.Set(i + j + 2*i*j)
}
}
cnt := bs.Count()
log.Println("bs.Count=", cnt, "/", bs.Len(), bs.Len()/(bs.Len()-cnt))
fp, err := os.Create("prime.dat")
if err != nil {
log.Panic("file open error")
}
defer fp.Close()
var primes = intseq.NewIntSeq()
primes.Add(2)
for i := uint(1); i < maxvv; i++ {
if !bs.Test(i) {
primes.Add(uint64(i*2 + 1))
}
}
primes.Write(fp)
}
func main() {
var maxv = uint(65536)
args := os.Args[1:len(os.Args)]
log.Println("args", args)
if len(args) != 0 {
if _, err := os.Stat(args[0]); err == nil {
dumpfile(args[0])
return
}
maxv64, _ := strconv.ParseUint(args[0], 0, 64)
maxv = uint(maxv64)
}
var maxvv = uint(math.Sqrt(float64(maxv)))
log.Println("calculate primes", maxv, maxvv)
// var maxv uint = 65536
var bs = bitset.New(maxv)
for i := uint(2); i < maxvv; i++ {
if bs.Test(i) {
continue
}
for j := i; j*i < maxv; j++ {
bs.Set(j * i)
}
}
cnt := bs.Count()
log.Println("bs.Count=", cnt, "/", bs.Len(), bs.Len()/(bs.Len()-cnt))
fp, err := os.Create("prime.dat")
if err != nil {
log.Panic("file open error")
}
defer fp.Close()
var primes = intseq.NewIntSeq()
for i := uint(2); i < maxv; i++ {
if !bs.Test(i) {
primes.Add(uint64(i))
}
}
primes.Write(fp)
}
// calculate primes and write them to file
package main
import (
"log"
"math"
"os"
"strconv"
"github.com/wtnb75/intseq"
)
var primes = intseq.NewIntSeq()
func isPrime(n uint64) bool {
var m = uint64(math.Sqrt(float64(n)))
var ret = true
primes.Each(func(v uint64) bool {
if n%v == 0 {
ret = false
return true
}
if v > m {
return true
}
return false
})
return ret
}
func dumpfile(fn string) {