main.go

package main

import (
    "bufio"
    "fmt"
    "os"
    "path/filepath"
    "sort"
    "strings"
)

type WordCount struct {
    word  string
    count int
}

func main() {
    wordCounts := make(map[string]int)

    err := filepath.Walk(".", func(path string, info os.FileInfo, err error) error {
        if !info.Mode().IsRegular() {
            return nil
        }
        if !strings.HasSuffix(path, ".txt") {
            return nil
        }

        f, err := os.Open(path)
        if err != nil {
            return err
        }
        defer f.Close()

        scanner := bufio.NewScanner(f)
        scanner.Split(bufio.ScanWords)

        for scanner.Scan() {
            word := strings.ToLower(scanner.Text())
            if len(word) < 2 {
                continue
            }
            wordCounts[word] += 1
        }

        return scanner.Err()
    })

    if err != nil {
        fmt.Printf("Error: %s\n", err)
        return
    }

    wordArray := make([]WordCount, 0, len(wordCounts))
    for word, count := range wordCounts {
        wordArray = append(wordArray, WordCount{word: word, count: count})
    }

    sort.Slice(wordArray, func(i, j int) bool {
        return wordArray[i].count > wordArray[j].count
    })

    for _, wc := range wordArray[:10] {
        fmt.Printf("%d %s\n", wc.count, wc.word)
    }
}