// Zorah Fung, CSE 142
// An interactive game that gives the user randomly generated math expressions to solve.
// Continues to give user expressions until 3 expressions are answered incorrectly.

import java.util.*;
public class AdditionGame {
   public static void main(String[] args) {
      Scanner console = new Scanner(System.in);
      Random rand = new Random();
      
      int misses = 0;
      int points = 0;
      while (misses < 3) {
         boolean correct = playGame(console, rand);
         if (correct) {
            points++;
         } else {
            misses++;
         }
      }
      System.out.println("You earned " + points + " total points");
   }  
   
   // Asks the user to solve a single randomly generated mathematical expression
   // Uses the given Random to randomly generate the expression. Returns true
   // if the user answers expression correctly, false otherwise.
   // Note: We changed the return type from int to boolean since there are only
   //       two possible return values: user got it right or did not
   public static boolean playGame(Scanner console, Random rand) {
      int operands = rand.nextInt(4) + 2;
      int actualSum = 0;
      for (int i = 1; i <= operands - 1; i++) {
         int number = rand.nextInt(31);
         System.out.print(number + " + ");
         actualSum += number;
      }
      int lastNumber = rand.nextInt(31);
      actualSum += lastNumber;
      System.out.print(lastNumber + " = ");
      // Note: Remove debugging code before submitting your solution!
      // System.out.print("hint: " + actualSum + " "); for debugging.
      int guess = console.nextInt();
      if (actualSum != guess) {
         System.out.println("Wrong! The answer was " + actualSum);
         return false;
      }
      return true;
   }
}