package main

import (
	"fmt"
	"sort"
)

func main() {
	fmt.Println(groupAnagrams([]string{"a"}))
}

func groupAnagrams(strs []string) [][]string {
	hash := make(map[string][]int)
	result := make([][]string, 0)
	for value, str := range strs {
		runes := []rune(str)
		sort.Slice(runes, func(i, j int) bool {
			return runes[i] < runes[j]
		})
		if _, ok := hash[string(runes)]; ok {
			hash[string(runes)] = append(hash[string(runes)], value)
		} else {
			hash[string(runes)] = make([]int, 0)
			hash[string(runes)] = append(hash[string(runes)], value)
		}
	}
	for _, value := range hash {
		tmp := make([]string, 0)
		for _, value := range value {
			tmp = append(tmp, strs[value])
		}
		result = append(result, tmp)
	}
	return result

}