Update CheckDigit.java

APCSLowell · Apr 30, 2024 · 5302281 · 5302281
1 parent 89d5f76
commit 5302281
Showing 1 changed file with 11 additions and 1 deletion.
diff --git a/src/main/java/CheckDigit.java b/src/main/java/CheckDigit.java
@@ -8,6 +8,10 @@ public class CheckDigit
    public static int getCheck(int num) 
    {  
      /* to be implemented in part (a) */
+     int sum = 0;
+     for(int i = 1; i < getNumberOfDigits(num); i++)
+       sum += (8-i)*getDigit(num,1);
+     return sum%10;
    }
 
   /** Returns true if numWithCheckDigit is valid, or false    
@@ -18,7 +22,13 @@ public static int getCheck(int num)
    */     
    public static boolean isValid(int numWithCheckDigit)    
    {      
-     /* to be implemented in part (b) */    
+     /* to be implemented in part (b) */
+     int check = numWithCheckDigit%10;
+     int dog = numWithCheckDigit/10;
+     int newCheck = getCheck(dog);
+     if(check == newCheck)
+       return true;
+     return false;
    }    
 
    /** Returns the number of digits in num. */