package main

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

func main() {
	counts := make(map[string][]string)
	file := os.Args[1:]
	if len(file) == 0 {
		countLines(os.Stdin, counts)
	} else {
		for _, i := range file {
			f, err := os.Open(i)
			if err != nil {
				log.Print(err)
			}
			countLines(f, counts)
			f.Close()
		}
	}
	for lines, n := range counts {
		if len(n) > 1 {
			fmt.Printf("%v\t\"%s\"\n", n, strings.Trim(lines, " "))
		}
	}
}

func contains(slice []string, file string) bool {
	for _, i := range slice {
		if i == file {
			return true
		}
	}
	return false
}

func countLines(f *os.File, counts map[string][]string) {
	input := bufio.NewScanner(f)
	for input.Scan() {
		cur := counts[input.Text()]
		if !contains(cur, f.Name()) {
			cur = append(cur, f.Name())
			counts[input.Text()] = cur
		}
	}
}