multi dimensional list

main.go

package main

import (
	"fmt"
)

func main() {
	l := &l{}
	fmt.Printf("result=%v\n", sum(l, nil, l.dims()))
}

func sum(l *l, prefix []int, dims []int) int {
	if len(dims) == 0 {
		return l.get(prefix)
	}

	result := 0
	n := dims[0]
	for i := 0; i < n; i++ {
		newPrefix := make([]int, len(prefix)+1)
		for j := 0; j < len(prefix); j++ {
			newPrefix[j] = prefix[j]
		}
		newPrefix[len(prefix)] = i
		result += sum(l, newPrefix, dims[1:])
	}

	return result
}

type l struct{}

func (*l) get(ins []int) int {
	fmt.Printf("get %v\n", ins)
	return 0
}

func (*l) dims() []int {
	return []int{1, 2, 3}
}