Add edge tagging

fb_arc_set/generator.c

@@ -71,6 +71,7 @@ int main(int argc, char *argv[]) {
             char *v = strtok(NULL, "");
             edges[i-1].u = strtol(u, NULL, 10);
             edges[i-1].v = strtol(v, NULL, 10);
+            edges[i-1].chosen = false;
 
             if(num_nodes < edges[i-1].u)
                 num_nodes = edges[i-1].u;
@@ -80,20 +81,14 @@ int main(int argc, char *argv[]) {
     }
     num_nodes++; ///< Our first node is labeled 0, so we need to add 1 more
 
-    /// Declare arrays for unique nodes and for the chosen edges
+    /// Declare arrays for unique nodes
     int unique_nodes[num_nodes];
-    bool chosen_edges[num_edges];
 
     /// Filling the node array with the nodes
     for(int i=0; i < num_nodes; i++) {
         unique_nodes[i] = i;
     }
 
-    /// Marking all edges as not chosen
-    for(int i=0; i < num_edges; i++) {
-        chosen_edges[i] = false;
-    }
-
     /// Allocate resources for circular buffer
     int wr_pos = 0;
     buffer_shmfd = create_shmfd(BUFF_SHM_NAME);
@@ -104,19 +99,40 @@ int main(int argc, char *argv[]) {
     use_sem = open_sem(USE_SEM_NAME, 0, 1);
     mutex = open_sem(MUTEX_NAME, 1, 1);
 
-    int best_solution = num_edges - 1; ///< Set a basic best solution
+    /// Declaring buffer arrays and variables
-
+    int current_best = num_edges - 1; ///< Set a basic best solution
-    /// Declaring buffer arrays
     int buf_nodes[num_nodes];
-    int buf_chosen_edges[num_edges];
+    edge_t buf_edges[num_edges];
+    int new_best = 0;
 
     while(terminate != true && circ_buffer -> finished != true) { ///< Loop until told to stop or until an acyclic solution is discovered
         /// Copy the original into a buffer array and shuffle it
         memcpy(buf_nodes, unique_nodes, sizeof(unique_nodes));
         shuffle(buf_nodes, num_nodes);
 
-        /// Reset the chosen status of the array
+        /// Reset the chosen status of the edges
-        memcpy(buf_chosen_edges, chosen_edges, sizeof(chosen_edges));
+        memcpy(buf_edges, edges, sizeof(edges));
+
+        new_best = 0; ///< Reset the new_besy counter
+        for(int i=0; i < num_edges; i++) {
+            if(new_best >= SET_MAX_SIZE || new_best >= num_edges)
+                break; ///< Skip if the solution is faulty
+
+            for(int j=0; j < num_nodes; j++) {
+                if(buf_nodes[j] == edges[i].u)
+                    break; ///< The first node comes before the second, break
+                else if(buf_nodes[j] == buf_edges[i].v) {
+                    buf_edges[i].chosen = true; ///< Found a correct edge, mark it as chosen
+                    new_best++;
+                    break;
+                }
+            }
+        }
+
+        /// Construct the new feedback arc set
+        if(new_best < current_best && new_best <= SET_MAX_SIZE) {
+            current_best = new_best;
+        }
     }
 
     exit(EXIT_SUCCESS);

fb_arc_set/shared/structs.c

@@ -6,6 +6,7 @@
 
 /// Struct for the edge
 typedef struct edge {
+    bool chosen;
     int u, v;
 } edge_t;