Game.go

package main

import (
	"fmt"
	"math/rand"
	"os"
	"strconv"
	"time"
)

// type Gamer interface {
// 	Check() (bool, string)
// 	Play()
// }

type Game struct {
	Count int
	Limit int
	Secret int
}

func (game *Game) Check (guess int) (bool, string) {
	game.Count += 1

	if guess == game.Secret {
		return true, ""
	} else if guess < game.Secret {
		return false, "low"
	} else {
		return false, "high"
	}
}

func (game *Game) Play (fn func (int, int, string) int) {
	var guess int
	var hint string
	var success bool

	for {
		guess = fn(game.Limit, guess, hint)

		success, hint = game.Check(guess)

		if success || game.Count > game.Limit {
			break
		} else {
			fmt.Println(fmt.Sprintf("Your guess (%d) is too %s.", guess, hint))
		}
	}

	if game.Count > game.Limit {
		fmt.Println(fmt.Sprintf("Sorry! The secret number was %d.", game.Secret))
	} else {
		fmt.Println(fmt.Sprintf("Congratulations! Correctly guessed the secret number (%d) in %d guesses.", guess, game.Count))
	}
}

type Solver struct {
	Range []int
}

func (solver Solver) Rand (limit int, guess int, hint string) int {
	return 1 + rand.Intn(limit)
}

func (solver *Solver) Smart (limit int, guess int, hint string) int {
	if guess == 0 || hint == "" {
		solver.Range[0] = 1
		solver.Range[1] = limit
	} else {
		if hint == "high" {
			solver.Range[1] = guess
		} else {
			solver.Range[0] = guess
		}
	}

	return 1 + solver.Range[0] + rand.Intn(solver.Range[1] - solver.Range[0])
}

// cmd: go run Game.go 100
func main () {
	rand.Seed(time.Now().UnixNano())

	var limit, _ = strconv.Atoi(os.Args[1])
	var secret int = (1 + rand.Intn(limit))
	fmt.Println(fmt.Sprintf("The secret is %d.", secret))

	var solver = Solver{[]int {1, limit}}

	var game = Game{0, limit, secret}
	// game.Play(solver.Rand)
	game.Play(solver.Smart)
}