Data commit

Task/Mastermind/Go/mastermind.go

@@ -0,0 +1,188 @@
+package main
+
+import (
+	"errors"
+	"flag"
+	"fmt"
+	"log"
+	"math/rand"
+	"strings"
+	"time"
+)
+
+func main() {
+	log.SetPrefix("mastermind: ")
+	log.SetFlags(0)
+	colours := flag.Int("colours", 6, "number of colours to use (2-20)")
+	flag.IntVar(colours, "colors", 6, "alias for colours")
+	holes := flag.Int("holes", 4, "number of holes (the code length, 4-10)")
+	guesses := flag.Int("guesses", 12, "number of guesses allowed (7-20)")
+	unique := flag.Bool("unique", false, "disallow duplicate colours in the code")
+	flag.Parse()
+
+	rand.Seed(time.Now().UnixNano())
+	m, err := NewMastermind(*colours, *holes, *guesses, *unique)
+	if err != nil {
+		log.Fatal(err)
+	}
+	err = m.Play()
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+
+type mastermind struct {
+	colours int
+	holes   int
+	guesses int
+	unique  bool
+
+	code   string
+	past   []string // history of guesses
+	scores []string // history of scores
+}
+
+func NewMastermind(colours, holes, guesses int, unique bool) (*mastermind, error) {
+	if colours < 2 || colours > 20 {
+		return nil, errors.New("colours must be between 2 and 20 inclusive")
+	}
+	if holes < 4 || holes > 10 {
+		return nil, errors.New("holes must be between 4 and 10 inclusive")
+	}
+	if guesses < 7 || guesses > 20 {
+		return nil, errors.New("guesses must be between 7 and 20 inclusive")
+	}
+	if unique && holes > colours {
+		return nil, errors.New("holes must be > colours when using unique")
+	}
+
+	return &mastermind{
+		colours: colours,
+		holes:   holes,
+		guesses: guesses,
+		unique:  unique,
+		past:    make([]string, 0, guesses),
+		scores:  make([]string, 0, guesses),
+	}, nil
+}
+
+func (m *mastermind) Play() error {
+	m.generateCode()
+	fmt.Printf("A set of %s has been selected as the code.\n", m.describeCode(m.unique))
+	fmt.Printf("You have %d guesses.\n", m.guesses)
+	for len(m.past) < m.guesses {
+		guess, err := m.inputGuess()
+		if err != nil {
+			return err
+		}
+		fmt.Println()
+		m.past = append(m.past, guess)
+		str, won := m.scoreString(m.score(guess))
+		if won {
+			plural := "es"
+			if len(m.past) == 1 {
+				plural = ""
+			}
+			fmt.Printf("You found the code in %d guess%s.\n", len(m.past), plural)
+			return nil
+		}
+		m.scores = append(m.scores, str)
+		m.printHistory()
+		fmt.Println()
+	}
+	fmt.Printf("You are out of guesses. The code was %s.\n", m.code)
+	return nil
+}
+
+const charset = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+const blacks = "XXXXXXXXXX"
+const whites = "OOOOOOOOOO"
+const nones = "----------"
+
+func (m *mastermind) describeCode(unique bool) string {
+	ustr := ""
+	if unique {
+		ustr = " unique"
+	}
+	return fmt.Sprintf("%d%s letters (from 'A' to %q)",
+		m.holes, ustr, charset[m.colours-1],
+	)
+}
+
+func (m *mastermind) printHistory() {
+	for i, g := range m.past {
+		fmt.Printf("-----%s---%[1]s--\n", nones[:m.holes])
+		fmt.Printf("%2d:  %s : %s\n", i+1, g, m.scores[i])
+	}
+}
+
+func (m *mastermind) generateCode() {
+	code := make([]byte, m.holes)
+	if m.unique {
+		p := rand.Perm(m.colours)
+		for i := range code {
+			code[i] = charset[p[i]]
+		}
+	} else {
+		for i := range code {
+			code[i] = charset[rand.Intn(m.colours)]
+		}
+	}
+	m.code = string(code)
+	//log.Printf("code is %q", m.code)
+}
+
+func (m *mastermind) inputGuess() (string, error) {
+	var input string
+	for {
+		fmt.Printf("Enter guess #%d: ", len(m.past)+1)
+		if _, err := fmt.Scanln(&input); err != nil {
+			return "", err
+		}
+		input = strings.ToUpper(strings.TrimSpace(input))
+		if m.validGuess(input) {
+			return input, nil
+		}
+		fmt.Printf("A guess must consist of %s.\n", m.describeCode(false))
+	}
+}
+
+func (m *mastermind) validGuess(input string) bool {
+	if len(input) != m.holes {
+		return false
+	}
+	for i := 0; i < len(input); i++ {
+		c := input[i]
+		if c < 'A' || c > charset[m.colours-1] {
+			return false
+		}
+	}
+	return true
+}
+
+func (m *mastermind) score(guess string) (black, white int) {
+	scored := make([]bool, m.holes)
+	for i := 0; i < len(guess); i++ {
+		if guess[i] == m.code[i] {
+			black++
+			scored[i] = true
+		}
+	}
+	for i := 0; i < len(guess); i++ {
+		if guess[i] == m.code[i] {
+			continue
+		}
+		for j := 0; j < len(m.code); j++ {
+			if i != j && !scored[j] && guess[i] == m.code[j] {
+				white++
+				scored[j] = true
+			}
+		}
+	}
+	return
+}
+
+func (m *mastermind) scoreString(black, white int) (string, bool) {
+	none := m.holes - black - white
+	return blacks[:black] + whites[:white] + nones[:none], black == m.holes
+}