Added cmd line arguments

src/main.cpp

@@ -2,9 +2,10 @@
 # include <iostream>
 # include <iomanip>
 # include <ctime>
+#include <stdio.h>
 # include "fire.h"
 
-int main ( ) 
+int main (int argc, char* argv[]) 
 
 //****************************************************************************80
 //
@@ -18,15 +19,38 @@ int main ( )
 //
 {
   int **forest;
-  int forest_size = 20;
+  int forest_size;
   int i_ignite;
   int j_ignite;
-  int offset;
   double percent_burned = 0.0;
   double prob_spread = 0.5;
   int seed;
   double u;
 
+  if (argc<3 || argc>3)
+  {
+      printf("Usage: fire forest_size seed\n");
+      printf("  forest_size        number of trees in x-direction and y-direction\n");
+      printf("  seed        for random fire ignition\n");
+      exit(1);
+  }
+
+  // read forest_size
+  forest_size = atoi(argv[1]);
+  if (forest_size < 1)
+  {
+      fprintf(stderr, "forest_size must be positive integer\n");
+      exit(-1);
+  }
+
+  // read seed
+  seed = atoi(argv[2]);
+  if (seed < 1)
+  {
+      fprintf(stderr, "seed must be positive integer\n");
+      exit(-1);
+  }
+
   timestamp ( );
   std::cout << "\n";
   std::cout << "FIRE_SERIAL\n";
@@ -36,8 +60,6 @@ int main ( )
 //
 //  Initialize the random number generator.
 //
-  offset = 0;
-  seed = seed_by_time ( offset );
   std::cout << "  The random number generator is seeded by " << seed << ".\n";
   srand ( seed );
 //