added my solution (gophercises#15)

Signed-off-by: Vivek Singh <[email protected]>

added my solution

fixed issue with blocking input

added my solution

Signed-off-by: Vivek Singh <[email protected]>

added my solution

students/viveksyngh/problems.csv

@@ -0,0 +1,12 @@
+5+5,10
+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

students/viveksyngh/quiz.go

@@ -0,0 +1,94 @@
+package main
+
+import (
+	"encoding/csv"
+	"os"
+	"fmt"
+	"strings"
+	"log"
+	"flag"
+	"time"
+	"math/rand"
+) 
+
+type Question struct {
+	question string
+	answer string
+}
+
+func getQuestions(filePath string) ([]Question) {
+	file, err := os.Open(filePath)
+	if(err != nil){
+		log.Fatal("Failed to open file.")
+	}
+	reader := csv.NewReader(file)
+	questionList, err := reader.ReadAll()
+	if(err != nil) {
+		log.Fatal("Failed to parse CSV file.")
+	}
+	questions := make([]Question, 0)
+
+	for _, question := range questionList {
+			questions = append(questions, Question{strings.TrimSpace(question[0]), 
+													strings.TrimSpace(question[1])})
+	}
+	return questions
+}
+
+func Quiz(questions []Question, timer *time.Timer) (score int){
+
+	for i, question := range questions {
+		fmt.Printf("Problem #%d %s : ", i + 1, question.question)
+		answerChannel := make(chan string)
+		go func() {
+			var userAnswer string
+			fmt.Scanln(&userAnswer)
+			answerChannel <- userAnswer
+		}()
+
+		select {
+			case <-timer.C:
+				fmt.Println("\nTimeout")
+				return score
+			case userAnswer := <- answerChannel:
+				if(strings.TrimSpace(userAnswer) == question.answer) {
+					score += 1
+				}
+		}
+	}
+	return score
+}
+
+func randomize(questions []Question) []Question{
+	n := len(questions)
+	for i := n-1; i>0; i-- {
+		j := rand.Intn(i)
+		temp := questions[i]
+		questions[i] = questions[j]
+		questions[j] = temp
+	}
+	return questions
+}
+
+var csvPath string
+var timeout int
+var shuffle bool
+
+func init() {
+	flag.StringVar(&csvPath, "csv", "problems.csv", "a CSV file in format of 'question,answer'")
+	flag.IntVar(&timeout, "limit", 30, "The time limit of the quiz in seconds")
+	flag.BoolVar(&shuffle, "shuffle", false, "Shuffle the questions (default 'false')")
+}
+
+func main() {
+	flag.Parse()
+	fmt.Print("Hit Enter to start the timer:")
+	questions := getQuestions(csvPath)
+	if(shuffle) {
+		questions = randomize(questions)
+	}
+	fmt.Scanln()
+	timer := time.NewTimer(time.Second * time.Duration(timeout))
+	score := Quiz(questions, timer)
+	fmt.Printf("Your scored %d out of %d\n", score, len(questions))
+}