Fix path reconstruction

Previous path computed was the set of opened tiles

main.cc

@@ -158,15 +158,19 @@ class World
 			bool r = false;
 
 			bool explored[size];
+			unsigned int previous[size];
 
-			stack<unsigned int> open;
-			open.push(s0);
-
-			for (unsigned int k(0); k < size; k ++)
+			for (unsigned int k(0); k < size; k ++) {
 				explored[k] = false;
+				previous[k] = k;
+			}
 
 			explored[s0] = true;
 
+
+			stack<unsigned int> open;
+			open.push(s0);
+
 			int current;
 			int neighbour;
 			unsigned int succs[4];
@@ -181,22 +185,28 @@ class World
 				for (unsigned int i(0); i < nbSuccs; i++) {
 					neighbour = succs[i];
 
-					if (!explored[neighbour])
+					if (!explored[neighbour]) {
 						open.push(neighbour);
+						previous[neighbour] = current;
+					}
 				}
 
-				// Build path
-				path.push_back(current);
-
 				// Current tile is now processed
 				explored[current] = true;
 
 				// Stop if target found
 				r = (current == target);
 
-
 			} while (!r && !open.empty());
 
+			// Build path
+			if (r) {
+				do {
+					path.push_back(current);
+					current = previous[current];
+				} while (current != s0);
+			}
+
 			return r;
 		} 
 };