1 files changed, 46 insertions, 0 deletions
diff --git a/challenge-169/ulrich-rieke/cpp/ch-1.cpp b/challenge-169/ulrich-rieke/cpp/ch-1.cpp
new file mode 100644
index 0000000000..2d4d8011f4
--- /dev/null
+++ b/challenge-169/ulrich-rieke/cpp/ch-1.cpp
@@ -0,0 +1,46 @@
+#include <iostream>
+#include <vector>
+#include <string>
+#include <algorithm>
+
+std::vector<int> primeDecompose( int n ) {
+  std::vector<int> primeFactors ;
+  int current = 2 ;
+  while ( n != 1 ) {
+      if ( n % current == 0 ) {
+        primeFactors.push_back( current ) ;
+        n /= current ;
+      }
+      else {
+        current++ ;
+      }
+  }
+  return primeFactors ;
+}
+
+bool isBrilliant( int n ) {
+  std::vector<int> primeFactors( primeDecompose( n ) ) ;
+  if ( primeFactors.size( ) == 2 ) {
+      std::vector<std::string> primeNumbers( 2 ) ;
+      std::transform( primeFactors.begin( ) , primeFactors.end( ) ,
+        primeNumbers.begin( ) , []( int i ){ return std::to_string( i ) ;} ) ;
+      return primeNumbers.begin()->length( ) == primeNumbers.back().length( ) ;
+  }
+  else {
+      return false ;
+  }
+}
+
+int main( ) {
+  std::vector<int> brilliantNumbers ;
+  int current = 2 ;
+  while ( brilliantNumbers.size( ) != 20 ) {
+      if ( isBrilliant( current ) )
+    brilliantNumbers.push_back( current ) ;
+      current++ ;
+  }
+  for ( int i : brilliantNumbers )
+      std::cout << i << " " ;
+  std::cout << std::endl ;
+  return 0 ;
+}