#include <stdio.h>
#include <stdbool.h>
#include "Graph.h"

#define MAX_NODES 1000

bool visited[MAX_NODES];

bool hamiltonR(Graph g, int nV, Vertex v, Vertex dest, int d) {
// v = current vertex considered
// dest = destination vertex
// d = distance "remaining" until path found

   Vertex w;
   if (v == dest) {
      return (d == 0);
   } else {
      visited[v] = true;
      for (w = 0; w < nV; w++) {
	 if (adjacent(g, v, w) && !visited[w]) {
	    if (hamiltonR(g, nV, w, dest, d-1)) {
	       return true;
	    }
	 }
      }
   }
   visited[v] = false;
   return false;
}

bool hasHamiltonianPath(Graph g, int nV, Vertex src, Vertex dest) {
   Vertex v;
   for (v = 0; v < nV; v++)
      visited[v] = false;
   return hamiltonR(g, nV, src, dest, nV-1);
}

int main(void) {
   Edge e;
   int n;

   printf("Enter the number of vertices: ");
   scanf("%d", &n);
   Graph g = newGraph(n);

   Vertex src, dest;
   printf("Enter source node: ");
   scanf("%d", &src);
   printf("Enter destination node: ");
   scanf("%d", &dest);
   
   printf("Enter an edge (from): ");
   while (scanf("%d", &e.v) == 1) {
      printf("Enter an edge (to): ");
      scanf("%d", &e.w);
      insertEdge(g, e);
      printf("Enter an edge (from): ");
   }
   printf("Finished.\n");

   printf("The graph has ");
   if (hasHamiltonianPath(g, n, src, dest))
      printf("a");
   else
      printf("no");
   printf(" Hamiltonian path from %d to %d.\n", src, dest);

   freeGraph(g);
   return 0;
}


// By 
//  .----------------.  .----------------.  .----------------.  .-----------------.  .----------------.  .----------------. 
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// | |    _| |_     | || |   \ `--' /   | || | _/ /    \ \_ | || | _| |_\   |_  | | | |  _| |  | |_  | || |  \  `--'  /  | |
// | |   |_____|    | || |    `.__.'    | || ||____|  |____|| || ||_____|\____| | | | | |____||____| | || |   `.____.'   | |
// | |              | || |              | || |              | || |              | | | |              | || |              | |
// | '--------------' || '--------------' || '--------------' || '--------------' | | '--------------' || '--------------' |
//  '----------------'  '----------------'  '----------------'  '----------------'   '----------------'  '----------------' 
 
//  Email :    z5261243@unsw.edu.au
//             hhoanhtuann@gmail.com