3 files changed, 65 insertions, 0 deletions

diff --git a/cpp/examples/variations.cpp b/cpp/examples/variations.cpp
new file mode 100644
index 0000000..3c6421d
--- /dev/null
+++ b/cpp/examples/variations.cpp
@@ -0,0 +1,15 @@
+/* A simple example showing how to move a cube and print it in H48 format. */
+
+#include "../nissy.h"
+#include <iostream>
+
+int main() {
+        std::string moves = "R U' Bw2 M D' x' F B(E2 F D B' Lw2 U2 U' S2 B)";
+        auto v = std::get<nissy::variation>(nissy::variation::get("lastqt"));
+        auto variations = v.find_variations(moves).solutions;
+
+        std::cout << "Changing the last quarter turn of " << moves << " gives:"
+            << std::endl << variations;
+
+        return 0;
+}
diff --git a/cpp/nissy.cpp b/cpp/nissy.cpp
index 90fcf20..6ca4884 100644
--- a/cpp/nissy.cpp
+++ b/cpp/nissy.cpp
@@ -12,6 +12,7 @@ extern "C" {
         long long nissy_inverse(const char *, char *);
         long long nissy_applymoves(const char *, const char *, char *);
         long long nissy_applytrans(const char *, const char *, char *);
+        long long nissy_variations(const char *, const char *, size_t, char*);
         long long nissy_getcube(long long, long long, long long, long long,
             long long, const char *, char *);
         long long nissy_solverinfo(const char *, char *);
@@ -44,6 +45,7 @@ namespace nissy {
         const error error::INVALID_MOVES{-20};
         const error error::INVALID_TRANS{-30};
         const error error::INVALID_SOLVER{-50};
+        const error error::INVALID_VARIATION{-51};
         const error error::NULL_POINTER{-60};
         const error error::BUFFER_SIZE{-61};
         const error error::DATA{-70};
@@ -62,10 +64,42 @@ namespace nissy {
                 constexpr size_t TRANSFORMATION = 12;
                 constexpr size_t SOLVE_STATS = 10;
                 constexpr size_t DATAID = 255;
+                constexpr size_t MOVES = 1000;
         }
 
         bool error::ok() const { return value >= 0; }
 
+        variation::variation(const std::string& str) : name{str} {}
+
+        variation::variations_result
+        variation::find_variations(const std::string& moves)
+        {
+                variation::variations_result result;
+
+                const size_t len = 3 * size::MOVES * 16;
+                result.solutions.resize(len);
+
+                auto err = nissy_variations(moves.c_str(), name.c_str(), len,
+                    result.solutions.data());
+
+                int size = result.solutions.find_first_of('\0');
+                result.solutions.resize(size);
+                result.err = error{err};
+
+                return result;
+        }
+
+        std::variant<variation, error>
+        variation::get(const std::string& name) {
+                char result[10];
+                variation s(name);
+
+                if (nissy_variations("", name.c_str(), 10, result) < 0)
+                        return error::INVALID_VARIATION;
+                else
+                        return s;
+        }
+
         cube::cube() {}
 
         error cube::move(const std::string& moves)
diff --git a/cpp/nissy.h b/cpp/nissy.h
index 199af10..74bbd32 100644
--- a/cpp/nissy.h
+++ b/cpp/nissy.h
@@ -39,6 +39,7 @@ namespace nissy {
                 static const error INVALID_MOVES;
                 static const error INVALID_TRANS;
                 static const error INVALID_SOLVER;
+                static const error INVALID_VARIATION;
                 static const error NULL_POINTER;
                 static const error BUFFER_SIZE;
                 static const error DATA;
@@ -63,6 +64,21 @@ namespace nissy {
                 static const compare_result DIFFERENT;
         };
 
+        class variation {
+        public:
+                struct variations_result {
+                        error err;
+                        std::string solutions;
+                };
+
+                const std::string name;
+
+                variations_result find_variations(const std::string&);
+                static std::variant<variation, error> get(const std::string&);
+        private:
+                variation(const std::string&);
+        };
+
         class cube {
         public:
                 cube();