grains.go

grains.go

package grains

import "errors"

func Square(i int) (uint64, error) {
	// fail fast
	if i < 1 || i > 64 {
		return 0, errors.New("square is out of range")
	}

	// use binay shift
	var result uint64 = 1 << (i - 1)

	return result, nil
}

func Total() uint64 {
	// Total is equal to 65 squares -1
	result, _ := Square(65)

	return result - 1
}