find items exclusive to two lists

exclusive.go

package main

import (
	"bufio"
	"fmt"
	"os"
	"strings"
)

func main() {
	a := getList("a.txt")
	b := getList("b.txt")
	fmt.Println(exclusive(a, b))
}

func getList(filename string) []string {
	f, err := os.Open(filename)
	if err != nil {
		panic(err)
	}
	r := []string{}
	s := bufio.NewScanner(f)
	for s.Scan() {
		l := s.Text()
		r = append(r, strings.TrimSpace(l))
	}
	return r
}

func exclusive(a, b []string) ([]string, []string) {
	ma := make(map[string]bool, len(a))
	mb := make(map[string]bool, len(b))
	mm := make(map[string]bool)
	for _, v := range a {
		ma[v] = true
		mm[v] = true
	}
	for _, v := range b {
		mb[v] = true
		mm[v] = true
	}
	nota := []string{}
	notb := []string{}
	for v, _ := range mm {
		if _, ok := mb[v]; !ok {
			notb = append(notb, v)
		}
		if _, ok := ma[v]; !ok {
			nota = append(nota, v)
		}
	}
	return nota, notb
}