import cs1.Keyboard;

public class Math_skill2
{
	public static void main (String[] args)
	{
		int randnum1=0, randnum2=0;
		int user_ans=0, ans=0;
		char repeat='y';

		do
		{
			System.out.print ("\nEnter desirable skill level (1-3): \t");
			int skill = Keyboard.readInt();

			while ( skill <= 0 || skill > 3 )
			{
				System.out.print ("\nThe skill level must be 1, 2, or 3: \t");
				skill = Keyboard.readInt();
			}

			System.out.print ("\nEnter the operator (*, /, +, or -): \t");
			char operator = Keyboard.readChar();

			System.out.print ("\nHow many questions you want to answer?: ");
			int numQuestions= Keyboard.readInt();

			System.out.println ("\nCalculate the answer:");
			System.out.println ("*********************\n");

			for ( int i = 1; i <= numQuestions; i++ )
			{

//-----------------------------------------------generate 2 random numbers
				switch (skill)
				{
					case 1:
						randnum1=(int)(Math.random()*10);
						randnum2=(int)(Math.random()*10);
						break;
					case 2:
						randnum1=(int)(Math.random()*100);
						randnum2=(int)(Math.random()*100);
						break;
					case 3:
						randnum1=(int)(Math.random()*1000);
						randnum2=(int)(Math.random()*1000);
				}
//----------------------------------------------------------------------

				switch (operator)
				{
					case '*':
						System.out.print (randnum1+ " * " +randnum2+ " = ");
						ans = randnum1 * randnum2;
						break;
					case '/':
						System.out.print (randnum1+ " / " +randnum2+ " = ");
						ans = randnum1 / randnum2;
						break;
					case '+':
						System.out.print (randnum1+ " + " +randnum2+ " = ");
						ans = randnum1 + randnum2;
						break;
					case '-':
						System.out.print (randnum1+ " - " +randnum2+ " = ");
						ans = randnum1 - randnum2;
						break;
					//default:
				}

				user_ans = Keyboard.readInt();	//***get the user answer

				if (user_ans == ans)
				{
					System.out.println ("\nCorrect! \n\n");
				}
				else
				{
					System.out.println ("\nWrong... \n\n");
				}
			}

			System.out.print ("\n________________________________________\n");
			System.out.print ("\nDo you want to play again (Y/N)?  ");
			repeat = Keyboard.readChar();

		} while (repeat == 'Y' || repeat == 'y' );

		System.out.println("\n\nGoodbye!\n\n");
	}
}