From 74abcececfd3bb2098d6538fa4b079116e1b98ba Mon Sep 17 00:00:00 2001
From: Timo Kokkonen <kaapeli@itanic.dy.fi>
Date: Sat, 20 Jun 2009 12:07:30 +0300
Subject: [PATCH] generator: Add some basic placeholders for having sudoku
 generator

---
 .gitignore    |  1 +
 Makefile      | 14 +++++++++-----
 generator.cpp |  6 ++++++
 random.cpp    | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 random.h      |  6 ++++++
 sudoku.cpp    |  5 +++++
 sudoku.h      |  4 +++-
 7 files changed, 76 insertions(+), 6 deletions(-)
 create mode 100644 generator.cpp
 create mode 100644 random.cpp
 create mode 100644 random.h

diff --git a/.gitignore b/.gitignore
index c0e1426..0e4e597 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,3 +3,4 @@
 .*.o.d
 *~
 sudokusolver
+sudokugenerator
diff --git a/Makefile b/Makefile
index 29afb26..a5d8c81 100644
--- a/Makefile
+++ b/Makefile
@@ -2,14 +2,18 @@ CC=g++
 LD=ld
 CFLAGS=-Wall -O2 -g
 
-SUDOKUSOLVER_OBJS= solver.o sudoku.o
+SOLVER_OBJS= solver.o sudoku.o random.o
+GENERATOR_OBJS= generator.o sudoku.o random.o
 
-all: sudokusolver
+all: sudokusolver sudokugenerator
 
-sudokusolver: $(SUDOKUSOLVER_OBJS)
-	$(CC) $(SUDOKUSOLVER_OBJS) -o sudokusolver
+sudokusolver: $(SOLVER_OBJS)
+	$(CC) $(SOLVER_OBJS) -o sudokusolver
 
-.cpp.o:
+sudokugenerator: $(GENERATOR_OBJS)
+	$(CC) $(GENERATOR_OBJS) -o sudokugenerator
+
+cpp.o:
 	$(CC) -MMD -MF .$@.d $(CFLAGS) -c $< -o $@
 
 clean:
diff --git a/generator.cpp b/generator.cpp
new file mode 100644
index 0000000..a578118
--- /dev/null
+++ b/generator.cpp
@@ -0,0 +1,6 @@
+#include "sudoku.h"
+
+int main(int argc, char *argv[])
+{
+	return 0;
+}
diff --git a/random.cpp b/random.cpp
new file mode 100644
index 0000000..62419c4
--- /dev/null
+++ b/random.cpp
@@ -0,0 +1,46 @@
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "random.h"
+
+#define RAND_BUF_SIZE	1024
+#define RND_DEV		"/dev/urandom"
+
+int get_random(void)
+{
+	static int rndbuf[RAND_BUF_SIZE];
+	static int index = RAND_BUF_SIZE;
+	int fd, error, i = 0, ret;
+
+	if (index < RAND_BUF_SIZE)
+		return rndbuf[index++];
+
+	fd = open(RND_DEV, O_RDONLY);
+	if (fd < 0) {
+		error = errno;
+		fprintf(stderr, "Error opening file %s: %s\n",
+			RND_DEV, strerror(error));
+		return -1;
+	}
+
+	do {
+		ret = read(fd, rndbuf + i,
+			  RAND_BUF_SIZE * (sizeof(rndbuf[0]) - i));
+		
+		if (ret <= 0) {
+			error = errno;
+			fprintf(stderr, "Error reading file %s: %s\n",
+				RND_DEV, strerror(error));
+			goto out;
+		}
+
+		i += ret;
+	} while (i < RAND_BUF_SIZE * sizeof(rndbuf[0]));
+ out:
+	close(fd);
+}
diff --git a/random.h b/random.h
new file mode 100644
index 0000000..f9c92c0
--- /dev/null
+++ b/random.h
@@ -0,0 +1,6 @@
+#ifndef _RANDOM_H
+#define _RANDOM_H
+
+int get_random(void);
+
+#endif
diff --git a/sudoku.cpp b/sudoku.cpp
index 7c4e208..3848d6e 100644
--- a/sudoku.cpp
+++ b/sudoku.cpp
@@ -3,6 +3,7 @@
 
 #include "sudoku.h"
 #include "debug.h"
+#include "random.h"
 
 #define EMPTY ' '
 
@@ -475,3 +476,7 @@ std::vector<sudoku> sudoku::solve_all()
 	return sudokus;
 }
 
+void sudoku::generate(int min_guesses)
+{
+
+}
diff --git a/sudoku.h b/sudoku.h
index 9575e7c..a0b8971 100644
--- a/sudoku.h
+++ b/sudoku.h
@@ -2,6 +2,7 @@
 #define SUDOKU_H
 
 #include <vector>
+#include <string>
 
 extern int verbose;
 
@@ -20,7 +21,8 @@ public:
 
 	std::string get_legal_numbers(const int col, const int row);
 	sudoku solve(int &solvable);
-	std::vector<sudoku> solve_all();
+	std::vector<sudoku> solve_all(void);
+	void generate(int min_guesses);
 
 	int recursion_depth;
 	int guesses;
-- 
2.45.0