Word Guessing Game

weirdie.go

package main

import (
	"bufio"
	"errors"
	"fmt"
	"io/ioutil"
	"math"
	"math/rand"
	"os"
	"strings"
	"time"
)

// grep '^\w\{5\}$' /usr/share/dict/words | tr '[:upper:]' '[:lower:]' | sort -u > five_letter_words
const WORDLEN = 5
const WORDFILE = "five_letter_words"

func load_words(wordfile string) (*[]string, error) {
	file, err := ioutil.ReadFile(wordfile)
	if err != nil {
		return nil, fmt.Errorf("Could not read from file %s: error: %s", wordfile, err)
	}

	words := strings.Split(string(file[:]), "\n")
	return &words, nil
}

func evaluate_guess(guess_str, actual_str string, words *[]string) (string, error) {
	// First see if guess is in words, invalid guesses are rejected
	// Since words is sorted, we binary search
	i := 0
	v := 0
	found := false
	guess := []rune(guess_str)
	actual := []rune(actual_str)
	words_length := len(*words)
	running := true
	for j := words_length - 2; running; j = int(math.Round(float64(j) / 2.0)) {
		if j == 1 {
			running = false
		}
		check_index := i + j
		if check_index > words_length {
			break
		}
		check := (*words)[check_index]
		v = strings.Compare(guess_str, check)
		if v == 0 {
			found = true
			break
		} else if v > 0 {
			i += j
		}
	}
	if !found {
		return "", errors.New("Guess not valid")
	}
	output := make([]rune, WORDLEN)
	for i := 0; i < WORDLEN; i++ {
		output[i] = rune('✖')
	}
	for i := 0; i < WORDLEN; i++ {
		if guess[i] == actual[i] {
			output[i] = rune('◎')
			actual[i] = rune(' ')
		}
	}
	for i := 0; i < WORDLEN; i++ {
		for j := 0; j < WORDLEN; j++ {
			if i != j && output[i] != rune('◎') && guess[i] == actual[j] {
				output[i] = rune('〇')
				actual[j] = rune(' ')
			}
		}
	}
	return string(output), nil
}

func main() {
	fmt.Println("Welcome to WeirdIe")
	fmt.Printf("Guess the %d letter word I'm thinking of\n", WORDLEN)
	fmt.Println("In 6 guesses or fewer!")
	rand.Seed(time.Now().UnixNano())
	words, _ := load_words(WORDFILE)
	actual := (*words)[rand.Intn(len(*words))]
	reader := bufio.NewReader(os.Stdin)
	for i := 1; i <= 6; i++ {
		guess := ""
		for {
			fmt.Printf("%d > ", i)
			guess, _ = reader.ReadString('\n')
			guess = strings.Replace(guess, "\n", "", -1)
			guess = strings.Replace(guess, "\r", "", -1)
			if len(guess) != WORDLEN {
				fmt.Printf("Guess must be %d letters, try again\n", WORDLEN)
				continue
			}
			result, err := evaluate_guess(guess, actual, words)
			if err != nil {
				fmt.Println(err)
			} else {
				fmt.Printf("    %s\n", result)
				break
			}
		}
		if guess == actual {
			fmt.Printf("You won in %d turns!\n", i)
			return
		}
	}
	fmt.Printf("Sorry, the word was \"%s\"\n", actual)
}