add: for statement loop exercises

13-loops/06-project-lucky-number-game/02-game/main.go

@@ -0,0 +1,63 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import (
+	"fmt"
+	"math/rand"
+	"os"
+	"strconv"
+	"time"
+)
+
+const (
+	maxTurns = 5 // less is more difficult
+	usage    = `Welcome to the Lucky Number Game! 🍀
+
+The program will pick %d random numbers.
+Your mission is to guess one of those numbers.
+
+The greater your number is, harder it gets.
+
+Wanna play?
+`
+)
+
+func main() {
+	rand.Seed(time.Now().UnixNano())
+
+	args := os.Args[1:]
+
+	if len(args) != 1 {
+		// fmt.Println("Pick a number.")
+		fmt.Printf(usage, maxTurns)
+		return
+	}
+
+	guess, err := strconv.Atoi(args[0])
+	if err != nil {
+		fmt.Println("Not a number.")
+		return
+	}
+
+	if guess < 0 {
+		fmt.Println("Please pick a positive number.")
+		return
+	}
+
+	for turn := 0; turn < maxTurns; turn++ {
+		n := rand.Intn(guess + 1)
+
+		if n == guess {
+			fmt.Println("🎉  YOU WIN!")
+			return
+		}
+	}
+
+	fmt.Println("☠️  YOU LOST... Try again?")
+}