Merge remote-tracking branch 'upstream/master'

1 files changed, 44 insertions, 0 deletions

diff --git a/challenge-169/adam-russell/java/ch-1.java b/challenge-169/adam-russell/java/ch-1.java
new file mode 100644
index 0000000000..09cdd62612
--- /dev/null
+++ b/challenge-169/adam-russell/java/ch-1.java
@@ -0,0 +1,44 @@
+import java.util.ArrayList;
+
+class Brilliant{
+    private static ArrayList primeFactors(long n){
+        ArrayList factors = new ArrayList();    
+        while (n % 2 == 0){
+            factors.add(new Long(2));
+            n = n / 2;
+        }
+        for(long i = 3; i <= Math.sqrt(n); i = i + 2){
+            while (n % i == 0){
+                factors.add(new Long(i));
+                n = n / i;
+            }
+        }
+        if(n > 2)
+            factors.add(new Long(n));
+        return factors;  
+    }
+    
+    private static boolean isBrilliant(int n){
+        ArrayList factors = primeFactors(n);
+        return factors.size() == 2 && ((Long)factors.get(0)).toString().length() == ((Long)factors.get(1)).toString().length();
+    }
+    
+    public static ArrayList nBrilliants(int n){
+        ArrayList brilliants = new ArrayList();
+        int i = 0;
+        do{
+            i++;
+            if(isBrilliant(i))
+                brilliants.add(new Integer(i));
+        }while(brilliants.size() < n);
+        return brilliants;
+    }
+
+    public static void main(String[] args){        
+        ArrayList brilliants = Brilliant.nBrilliants(20);
+        for(int i = 0; i < brilliants.size() - 1; i++){
+            System.out.print(brilliants.get(i) + ", ");
+        }
+        System.out.println(brilliants.get(brilliants.size() - 1));
+    }
+}
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