drum limb combinations

limb.go

package main

import (
	"fmt"
	"math/bits"
	"sort"
)

type Limb byte

const (
	RH Limb = 1 << iota
	LH
	RF
	LF
)

func (l Limb) Count() int {
	return bits.OnesCount(uint(l))
}

func (l Limb) StrikeString() string {
	s := make([]string, 4)
	if l&RH != 0 {
		s[0] = "RH"
	}
	if l&LH != 0 {
		s[1] = "LH"
	}
	if l&RF != 0 {
		s[2] = "RF"
	}
	if l&LF != 0 {
		s[3] = "LF"
	}
	return fmt.Sprintf("%-2s %-2s %-2s %-2s", s[0], s[1], s[2], s[3])
}

func main() {
	sets := []Limb{}
	for i := 1; i < 16; i++ {
		if Limb(i).Count() == 1 {
			continue
		}
		sets = append(sets, Limb(i))
	}
	sort.Slice(sets, func(i, j int) bool { return sets[i].Count() < sets[j].Count() })
	for i := len(sets) - 1; i >= 0; i-- {
		fmt.Println(sets[i].StrikeString())
	}
}

/*
String Sort
RH LH RF LF
RH LH RF
RH LH    LF
RH LH
RH    RF LF
RH    RF
RH       LF
   LH RF LF
   LH RF
   LH    LF
      RF LF

Limb Count Sort
4x1
RH LH RF LF

3x4
   LH RF LF
RH    RF LF
RH LH    LF
RH LH RF

2x6
      RF LF
   LH    LF
RH       LF
   LH RF
RH    RF
RH LH

*/