Quiz excercise (#35)

Author: kdlug

students/kdlug/main.go

@@ -0,0 +1,99 @@
+package main
+
+import (
+	"bufio"
+	"bytes"
+	"encoding/csv"
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"math/rand"
+	"os"
+	"strings"
+	"time"
+)
+
+func main() {
+	csvFile := flag.String("csv", "problems.csv", "csv file with questions and answers")
+	duration := flag.Int("time", 30, "quiz time limit")
+	randomize := flag.Bool("random", false, "randomize questions")
+
+	// Parse
+	flag.Parse()
+
+	reader := bufio.NewReader(os.Stdin)
+	questions := loadRecordsFromCsv(*csvFile)
+	correct := 0
+	total := len(questions) - 1
+
+	if *randomize {
+		questions = shuffle(questions)
+	}
+
+	fmt.Println("Total Questions:", total)
+	fmt.Println("Duration [s]:", *duration)
+
+	done := make(chan bool, 1)
+
+	go func() {
+		for i := 0; i < total; i++ {
+			fmt.Printf("Question #%d %s = ", i+1, questions[i][0])
+
+			answer, _ := reader.ReadString('\n')
+			// convert CRLF to LF
+			answer = strings.Replace(answer, "\n", "", -1)
+			answer = strings.ToLower(answer)
+			answer = strings.TrimSpace(answer)
+
+			// compare answer
+			if strings.Compare(questions[i][1], answer) == 0 {
+				correct++
+			}
+
+		}
+		done <- true
+	}()
+
+	select {
+	case <-done:
+		fmt.Println("Good Job!")
+
+	case <-time.After(time.Duration(*duration) * time.Second):
+		fmt.Println("\nYou reached maximum time.")
+	}
+
+	fmt.Println("Your score:", correct, "/", total)
+}
+
+// shuffle questions
+func shuffle(questions [][]string) [][]string {
+	s := rand.NewSource(time.Now().UnixNano())
+	r := rand.New(s)
+
+	for i := range questions {
+		np := r.Intn(len(questions) - 1)
+		questions[i], questions[np] = questions[np], questions[i]
+	}
+
+	return questions
+}
+
+func loadRecordsFromCsv(csvFile string) [][]string {
+
+	// load csv file into memory, returns bytes
+	content, err := ioutil.ReadFile(csvFile)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	r := csv.NewReader(bytes.NewReader(content)) // if we have string instead of btes we can use strings.NewReader(content)
+
+	records, err := r.ReadAll()
+
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	return records[1:len(records)]
+}

students/kdlug/problems.csv

@@ -0,0 +1,14 @@
+question,answer
+5+5,10
+7+3,10
+1+1,2
+8+3,11
+1+2,3
+8+6,14
+3+1,4
+1+4,5
+5+1,6
+2+3,5
+3+3,6
+2+4,6
+5+2,7