Fix completion checking in Killer Solo.

[sgt-puzzles.git] / puzzles.h

diff --git a/puzzles.h b/puzzles.h
index 0d5aeee14fe0b3b00bf88bea74c95243f87e9606..1847d9c7b8964a740061f79d5375785be901071c 100644 (file)
--- a/puzzles.h
+++ b/puzzles.h
@@ -467,6 +467,41 @@ void free_combi(combi_ctx *combi);
 /* divides w*h rectangle into pieces of size k. Returns w*h dsf. */
 int *divvy_rectangle(int w, int h, int k, random_state *rs);
 
+/*
+ * findloop.c
+ */
+struct findloopstate;
+struct findloopstate *findloop_new_state(int nvertices);
+void findloop_free_state(struct findloopstate *);
+/*
+ * Callback provided by the client code to enumerate the graph
+ * vertices joined directly to a given vertex.
+ *
+ * Semantics: if vertex >= 0, return one of its neighbours; if vertex
+ * < 0, return a previously unmentioned neighbour of whatever vertex
+ * was last passed as input. Write to 'ctx' as necessary to store
+ * state. In either case, return < 0 if no such vertex can be found.
+ */
+typedef int (*neighbour_fn_t)(int vertex, void *ctx);
+/*
+ * Actual function to find loops. 'ctx' will be passed unchanged to
+ * the 'neighbour' function to query graph edges. Returns FALSE if no
+ * loop was found, or TRUE if one was.
+ */
+int findloop_run(struct findloopstate *state, int nvertices,
+                 neighbour_fn_t neighbour, void *ctx);
+/*
+ * Query whether an edge is part of a loop, in the output of
+ * find_loops.
+ *
+ * Due to the internal storage format, if you pass u,v which are not
+ * connected at all, the output will be TRUE. (The algorithm actually
+ * stores an exhaustive list of *non*-loop edges, because there are
+ * fewer of those, so really it's querying whether the edge is on that
+ * list.)
+ */
+int findloop_is_loop_edge(struct findloopstate *state, int u, int v);
+
 /*
  * Data structure containing the function calls and data specific
  * to a particular game. This is enclosed in a data structure so