/* 
EXPECTED OUTPUT:

This program helps you practice multiplication
by asking you random multiplication questions
with numbers ranging from 1 to 20
and counting how many you solve correctly.

14 * 8 = 112
Correct!
5 * 12 = 60
Correct!
8 * 3 = 24
Correct!
5 * 5 = 25
Correct!
20 * 14 = 280
Correct!
19 * 14 = 256
Incorrect; the correct answer was 266
You solved 5 correctly.
*/

import java.util.*;

// Asks the user to do multiplication problems and scores them.
public class MultTutor {
    public static final int MAX = 20;
    
    public static void main(String[] args) {
        introduction();
        Scanner console = new Scanner(System.in);
        
        // loop until user gets one wrong
        int correct = 0;
        while (askQuestion(console)) {
            correct++;
        }
        
        System.out.println("You solved " + correct + " correctly.");
    }
    
    public static void introduction() {
        System.out.println("This program helps you practice multiplication");
        System.out.println("by asking you random multiplication questions");
        System.out.println("with numbers ranging from 1 to " + MAX);
        System.out.println("and counting how many you solve correctly.");
        System.out.println();
    }
    
    public static boolean askQuestion(Scanner console) {
        // pick two random numbers between 1 and 20 inclusive
        Random rand = new Random();
        int num1 = rand.nextInt(MAX) + 1;
        int num2 = rand.nextInt(MAX) + 1;
        
        System.out.print(num1 + " * " + num2 + " = ");
        int guess = console.nextInt();
        if (guess == num1 * num2) {
            System.out.println("Correct!");
            return true;
        } else {
            System.out.println("Incorrect; the correct answer was " + (num1 * num2));
            return false;
        }
    }
}