From e98267a6255d87cbb74118f43348f8a4c8a42f1f Mon Sep 17 00:00:00 2001
From: Eric Zhao <140433074+mykinglebron@users.noreply.github.com>
Date: Mon, 29 Apr 2024 23:18:21 -0700
Subject: [PATCH] Update CheckDigit.java

---
 src/main/java/CheckDigit.java | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/main/java/CheckDigit.java b/src/main/java/CheckDigit.java
index ee0092a..1c82d32 100644
--- a/src/main/java/CheckDigit.java
+++ b/src/main/java/CheckDigit.java
@@ -7,7 +7,11 @@ 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, i);
+     }
+     return sum%10;
    }
  
   /** Returns true if numWithCheckDigit is valid, or false    
@@ -18,7 +22,12 @@ public static int getCheck(int num)
    */     
    public static boolean isValid(int numWithCheckDigit)    
    {      
-     /* to be implemented in part (b) */    
+     int check= numWithCheckDigit % 10;
+     int num= numWithCheckDigit / 10;
+    int newCheck =getCheck(num);
+   if(newCheck==check){
+return true)}
+     else{return false;}
    }    
    
    /** Returns the number of digits in num. */