// CSE 142, Winter 2007
// Author: Martson Limsteppkai
//
// This program asks the user to do multiplication problems
// and counts how many the user got right.
// Uses a constant for the maximum value.

import java.util.*;

public class MultTutor {
    public static final int MAX = 50;

    public static void main(String[] args) {
        introduction();
        Scanner console = new Scanner(System.in);
        Random r = new Random();
        int count = 0;        

        // keep playing games until playRound returns false
        while (playRound(console, r)) {
            count++;
        }

        System.out.println("You got " + count + " right.");
    }
    
    // This method plays one round of the multiplication game
    // and returns true if the player was correct and false if incorrect.
    public static boolean playRound(Scanner console, Random r) {
        int num1 = r.nextInt(MAX) + 1;
        int num2 = r.nextInt(MAX) + 1;
        System.out.print(num1 + " * " + num2 + " = ");
        int guess = console.nextInt();

        // check whether guess was right, then print/return appropriate response
        if (num1 * num2 == guess) {
            System.out.println("Correct!");
            return true;
        } else {
            System.out.println("Incorrect; the correct answer was " + (num1 * num2));
            return false;
        }
    }
    
    // Prints a welcome message to the user.
    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();
    }
}