GuessChecker133.java

/*
 * Activity 1.3.2
 */
import java.util.Scanner;
 
public class GuessChecker133
{
  public static void main(String[] args)
  {
    /* Add any variables you will need throughout the program here. */
  
    // Generate the random number
    String targetStr = makeCode();
    
    //System.out.println(targetStr);  // uncomment for debugging
    
    // Break the random number into four variables.
    int r1 = Integer.parseInt(targetStr.substring(0, 1));
    int r2 = Integer.parseInt(targetStr.substring(1, 2));
    int r3 = Integer.parseInt(targetStr.substring(2, 3));
    int r4 = Integer.parseInt(targetStr.substring(3, 4));
    
    // Get the user's guess.
    String guess = getGuess();
    //System.out.println(guess);   // uncomment for debugging
    
    // Break the user's guess into four variables.
    int hits = 0;
    int nearHits= 0;
    int g1 = Integer.parseInt(guess.substring(0, 1));
    int g2 = Integer.parseInt(guess.substring(1, 2));
    int g3 = Integer.parseInt(guess.substring(2, 3));
    int g4 = Integer.parseInt(guess.substring(3, 4));
    
    if(r1==g1)
      hits++;
    if(r2==g2)
      hits++;
    if(r3==g3)
      hits++;
    if(r4==g4)
      hits++;
    if(g1==r1||g1==r2||g1==r3||g1==r4)
    {
      nearHits++;
    }
    if(g2==r1||g2==r2||g2==r3||g2==r4)
    {
      nearHits++;
    }
    if(g3==r1||g3==r2||g3==r3||g3==r4)
    {
      nearHits++;
    }
    if(g4==r1||g4==r2||g4==r3||g4==r4)
    {
      nearHits++;
    }
    System.out.println("Hits: "+hits+"\nNear hits: "+nearHits);
   
  }
 
  // Checks to ensure no duplicate digits in a int.
  public static boolean hasDupes(int num)
  { 
    boolean[] digs = new boolean[10];
    while (num > 0)
    {
      if (digs[num % 10])
        return true;
      digs[num % 10] = true;
      num /= 10;
    }
    return false;
  }
 
  // Creates a new random 4 digit code 1000-9999 with no duplicates.
  public static String makeCode() 
  { 
    int target = (int) (Math.random() * 9000 + 1000);
    while (hasDupes(target))
      target = (int) (Math.random() * 9000 + 1000);
    String targetStr = target + "";
    return targetStr;
  }
 
  // Prompts the user for a guess and repeats until valid guess is made.
  public static String getGuess() 
  { 
    Scanner sc = new Scanner(System.in);
    boolean validGuess = false;
    int userGuess = 0;
    while (!validGuess)
    {
      System.out.print("Guess a 4-digit number from 1000 to 9999 with no duplicate digits: ");
      userGuess = sc.nextInt();
      if (!(hasDupes(userGuess) || (userGuess < 1000))) 
        validGuess = true;
    }
    String userStr = userGuess + "";
    return userStr;
  }
}