1 files changed, 35 insertions, 0 deletions
diff --git a/challenge-097/ulrich-rieke/cpp/ch-1.cpp b/challenge-097/ulrich-rieke/cpp/ch-1.cpp
new file mode 100644
index 0000000000..d69135b4cc
--- /dev/null
+++ b/challenge-097/ulrich-rieke/cpp/ch-1.cpp
@@ -0,0 +1,35 @@
+#include <iostream>
+#include <cstdlib>
+#include <string>
+#include <algorithm>
+#include <iterator>
+
+char findCipher( char c, int shift ) {
+  static const std::string alphabet {"ABCDEFGHIJKLMNOPQRSTUVWXYZ"} ;
+  std::string mapped { alphabet.substr(26 - shift) } ;
+  std::reverse ( mapped.begin( ) , mapped.end( ) ) ;
+  mapped.append( alphabet.substr(0 , 26 - shift ) ) ;
+  if ( c == ' ' )
+      return ' ' ;
+  else {
+      auto found = std::find( alphabet.begin( ) , alphabet.end( ) , c );
+      return mapped[ static_cast<int>(std::distance(alphabet.begin( ), found))] ;
+  }
+}
+
+int main( int i , char* argv[ ] ) {
+  if ( i != 3 ) {
+      std::cerr << "usage: challenge097 <capital letter string> <leftshift>!\n" ;
+      return 1 ;
+  }
+  int leftshift = std::atoi( argv[ 2 ] ) ;
+  int realshift = leftshift % 26 ;
+  std::string plaintext( argv[ 1 ] ) ;
+  int len = plaintext.length( ) ;
+  std::string ciphertext ;
+  for ( char letter : plaintext ) {
+      ciphertext.push_back( findCipher ( letter , realshift ) ) ;
+  }
+  std::cout << ciphertext << std::endl ;
+  return 0 ;
+}