top.go

package hw03frequencyanalysis

import (
	"regexp"
	"sort"
)

var r = regexp.MustCompile(`\s+`)

func Top10(text string) []string {
	if len(text) == 0 {
		return nil
	}

	wordsMap := make(map[string]int)

	words := r.Split(text, -1)
	for _, word := range words {
		wordsMap[word]++
	}

	result := make([]string, 0, len(wordsMap))
	for name := range wordsMap {
		result = append(result, name)
	}

	sort.Slice(result, func(i, j int) bool {
		first := result[i]
		second := result[j]

		if wordsMap[first] == wordsMap[second] {
			return first < second
		}

		return wordsMap[first] > wordsMap[second]
	})

	return result[:10]
}