- Added solutions by Ulrich Rieke.

1 files changed, 42 insertions, 0 deletions

diff --git a/challenge-162/ulrich-rieke/cpp/ch-1.cpp b/challenge-162/ulrich-rieke/cpp/ch-1.cpp
new file mode 100644
index 0000000000..c4e833f850
--- /dev/null
+++ b/challenge-162/ulrich-rieke/cpp/ch-1.cpp
@@ -0,0 +1,42 @@
+#include <string>
+#include <vector>
+#include <iostream>
+
+std::vector<int> convert( std::string & numberstring ) {
+  std::vector<int> numbers ;
+  for ( int i = 0 ; i < numberstring.size( ) ; i++ ) {
+      if ( numberstring.substr( i , 1 ) != "-" ) {
+    numbers.push_back( std::stoi( numberstring.substr( i, 1) ) ) ;
+      }
+  }
+  return numbers ;
+}
+
+int main( ) {
+  std::cout << "Please enter an ISBN string with only 12 digits!\n" ;
+  std::string isbn ;
+  std::cin >> isbn ;
+  std::string converted ( isbn ) ;
+  std::vector<int> numbers { convert( converted ) } ;
+  while ( numbers.size( ) != 12 ) {
+      std::cout << "Enter an ISBN with only 12 digits, for exercise purposes!\n" ;
+      std::cin >> isbn ;
+      converted = isbn ;
+      numbers = convert( converted ) ;
+  }
+  std::cout << std::endl ;
+  std::vector<int> multipliers ;
+  for ( int i = 0 ; i < 6 ; i++ ) {
+      multipliers.push_back( 1 ) ;
+      multipliers.push_back( 3 ) ;
+  }
+  int sum = 0 ;
+  for ( int i = 0 ; i < 12 ; i++ ) {
+      sum += *(numbers.begin( ) + i ) * *(multipliers.begin( ) + i) ;
+  }
+  int check = 10 - ( sum % 10 ) ;
+  if ( check == 10 )
+      check == 0 ;
+  std::cout << "The ISBN is " << isbn << std::to_string( check ) << " !\n" ;
+  return 0 ;
+}