From 5355de2921126e2b75e24abd57e17556e22a6ed0 Mon Sep 17 00:00:00 2001
From: Sebastiano Tronto <sebastiano@tronto.net>
Date: Thu, 7 Aug 2025 15:09:46 +0200
Subject: Added API function for solution variations

---
 cpp/examples/variations.cpp | 15 +++++++++++++++
 cpp/nissy.cpp               | 34 ++++++++++++++++++++++++++++++++++
 cpp/nissy.h                 | 16 ++++++++++++++++
 3 files changed, 65 insertions(+)
 create mode 100644 cpp/examples/variations.cpp

(limited to 'cpp')

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();
-- 
cgit v1.3