1 files changed, 45 insertions, 0 deletions
diff --git a/challenge-306/ulrich-rieke/cpp/ch-2.cpp b/challenge-306/ulrich-rieke/cpp/ch-2.cpp
new file mode 100755
index 0000000000..6168957a91
--- /dev/null
+++ b/challenge-306/ulrich-rieke/cpp/ch-2.cpp
@@ -0,0 +1,45 @@
+#include <iostream>
+#include <string>
+#include <vector>
+#include <sstream>
+#include <algorithm>
+
+std::vector<std::string> split( const std::string & text , char delimiter ) {
+   std::vector<std::string> tokens ;
+   std::istringstream istr { text } ;
+   std::string word ;
+   while ( std::getline( istr , word , delimiter ) ) {
+      tokens.push_back( word ) ;
+   }
+   return tokens ;
+}
+
+int main( ) {
+   std::cout << "Enter some integers separated by whitespace!\n" ;
+   std::string line ;
+   std::getline( std::cin , line ) ;
+   auto tokens { split( line , ' ' ) } ;
+   std::vector<int> numbers ;
+   for ( auto s : tokens ) 
+      numbers.push_back( std::stoi( s ) ) ;
+   while ( numbers.size( ) > 1 ) {
+      std::sort( numbers.begin( ) , numbers.end( ) ) ;
+      int len = numbers.size( ) ;
+      if ( numbers[len - 2] == numbers[len - 1] ) {
+	 numbers.pop_back( ) ;
+	 numbers.pop_back( ) ;
+      }
+      else {
+         numbers[ len - 1 ] = numbers[ len - 1 ] - numbers[ len - 2 ] ;
+	 numbers.erase( numbers.begin( ) + len - 2 ) ;
+      }
+   }
+   if ( numbers.size( ) == 1 ) {
+      std::cout << *numbers.begin( ) ;
+   }
+   else {
+      std::cout << 0 ;
+   }
+   std::cout << '\n' ;
+   return 0 ;
+}