Anagram group

anagram_group.go

package main
import (
	"fmt"
	"strings"
)

func frequencyHash(word string) string {
	frequencyTable := [26]int{}
	for _, b := range word {
		ascii := int(b)
		//tolower
		if ascii >= int('A') && ascii <= int('Z') {
			ascii = int('a') + (ascii - int('A'))
		}
		ascii -= int('a')
		frequencyTable[ascii]++
	}
	// convert the frequency table to hash
	hash := []string{}
	for _, v := range frequencyTable {
		hash = append(hash, fmt.Sprintf("%s", v))
	}

	return strings.Join(hash, "-")
}

func group_anagrams(words []string) [][]string {
	m := make(map[string][]string)
	for _, word := range words {
		h := frequencyHash(word)
		m[h] = append(m[h], word)
	}

	res := [][]string{}
	for _, groups := range m {
		res = append(res, groups)
	}

	return res
}

func main() {
	words := []string{"eat", "tea", "tan", "ate", "bak", "ant"}
	res := group_anagrams(words)
	fmt.Println("anagram groups", res)
}