Changeset 16df684 in git

Timestamp:

Nov 4, 2017, 4:32:48 PM (6 years ago)

Author:

Karim Abou Zeid <karim23697@…>

Branches:

(u'spielwiese', 'fe61d9c35bf7c61f2b6cbf1b56e25e2f08d536cc')

Children:

7aa8ebd3a7ec021c4a466cfa15b50b7fc4daa44d

Parents:

5a5ef881f3af1708074c5c01b7add74757de7ef3

Message:

Fix existsRoute() to require at least one edge

File:

• Singular/LIB/fpadim.lib (modified) (3 diffs)

Singular/LIB/fpadim.lib

@@ -1215 +1215 @@
 "USAGE: existsRoute(G,v,u); G a graph, v and u vertices
 NOTE: don't pass anything to # (internal use for recursion)
-"
-{
-  if (v == u) {return (1);}
-
+@*    routes always have at least one edge
+"
+{
   int n = ncols(G);
 
@@ -1224 +1223 @@
   intvec visited;
   if (size(#) > 0) {
+    if (v == u) {return (1);} // don't check on first call so |route| >= 1 holds
     visited = #[1];
-  } else {
+  } else { // first call
     visited[n] = 0;
   }
@@ -1234 +1234 @@
   // recursive DFS
   for (int i = 1; i <= n; i++) {
-    if (G[v,i] && !visited[i]) {
+    if (G[v,i] && (!visited[i] || i == u)) { // i == u to allow routes from u to u
       if (existsRoute(G, i, u, visited)) {
         return (1);