mathtools/cmd/primeOmega.go

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2025-09-20 18:07:45 +00:00
/*
Copyright © 2025 filifa
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package cmd
import (
"fmt"
"github.com/spf13/cobra"
)
var primeOmegaN uint
func primeOmegaUpdateMultiples(sieve []uint, p uint, n uint) {
for q := p; ; q *= p {
// omega(a*b) = omega(a) + omega(b) if gcd(a,b) = 1
for i := 2 * q; i < n; i += q {
if i%(p*q) != 0 {
sieve[i] += sieve[q]
}
}
if p*q >= n {
break
}
}
}
func primeOmegaSieve(n uint) chan uint {
sieve := make([]uint, n)
for i := uint(0); i < n; i++ {
sieve[i] = 0
}
ch := make(chan uint)
go func() {
for i := uint(0); i < n; i++ {
if i == 0 || i == 1 || sieve[i] != 0 {
ch <- sieve[i]
continue
}
sieve[i] = 1
primeOmegaUpdateMultiples(sieve, i, n)
ch <- sieve[i]
}
close(ch)
}()
return ch
}
func primeOmega(cmd *cobra.Command, args []string) {
ch := primeOmegaSieve(primeOmegaN)
for i := 0; ; i++ {
v, ok := <-ch
if !ok {
break
}
if i == 0 {
continue
}
fmt.Println(v)
}
}
// primeOmegaCmd represents the primeOmega command
var primeOmegaCmd = &cobra.Command{
Use: "prime-omega -n N",
Short: "",
Long: ``,
Run: primeOmega,
}
func init() {
sieveCmd.AddCommand(primeOmegaCmd)
// Here you will define your flags and configuration settings.
// Cobra supports Persistent Flags which will work for this command
// and all subcommands, e.g.:
// primeOmegaCmd.PersistentFlags().String("foo", "", "A help for foo")
// Cobra supports local flags which will only run when this command
// is called directly, e.g.:
// primeOmegaCmd.Flags().BoolP("toggle", "t", false, "Help message for toggle")
primeOmegaCmd.Flags().UintVarP(&primeOmegaN, "limit", "n", 0, "upper limit")
primeOmegaCmd.MarkFlagRequired("limit")
}