#ifndef LOADER_H

 #define LOADER_H

 #include <map>

 #define LINE_LEN 1024

 template<typename Graph>

 void LoadGraph(Graph &G, char *filename) {

   FILE *file;

   if ((file = fopen(filename, "r")) == NULL) {

     printf("Could not open %s\n", filename);

     return;

   }

   int i, n1, n2;

   std::map<int, typename Graph::NodeIt> nmap;

   char line[LINE_LEN];

   while (fgets(line, LINE_LEN, file)) {

     switch (line[0]) {

       case 'n':

         nmap[atoi(line + 1)] = G.addNode();

         break;

       case 'a':

         n1 = atoi(line + 1);

         i = 1;

         while (isspace(line[i])) i++;

         while (isdigit(line[i])) i++;

         n2 = atoi(line + i);

         if (nmap.find(n1) == nmap.end()) {

           nmap[n1] = G.addNode();

         }

         if (nmap.find(n2) == nmap.end()) {

           nmap[n2] = G.addNode();

         }

         G.addEdge(nmap[n1], nmap[n2]);

         break;

     }

   }

 }

 #endif