Write a comment outlining a design for a rewritten faster solver.

[sgt/puzzles] / solo.c

diff --git a/solo.c b/solo.c
index 052ebef..7062194 100644 (file)
--- a/solo.c
+++ b/solo.c
@@ -1473,7 +1473,7 @@ static int solver_killer_sums(struct solver_usage *usage, int b,
     }
     assert(nsquares > 0);
 
-    if (nsquares > 4)
+    if (nsquares < 2 || nsquares > 4)
        return 0;
 
     if (!cage_is_region) {
@@ -2041,7 +2041,7 @@ static void solver(int cr, struct block_structure *blocks,
                                             );
                if (ret > 0) {
                    changed = TRUE;
-                   kdiff = max(kdiff, DIFF_KINTERSECT);
+                   kdiff = max(kdiff, DIFF_KSUMS);
                } else if (ret < 0) {
                    diff = DIFF_IMPOSSIBLE;
                    goto got_result;
@@ -2402,7 +2402,7 @@ static void solver(int cr, struct block_structure *blocks,
                    scratch->indexlist[i*cr+n-1] = cubepos2(diag1(i), n);
             ret = solver_set(usage, scratch, scratch->indexlist
 #ifdef STANDALONE_SOLVER
-                            , "set elimination, \\-diagonal"
+                            , "set elimination, /-diagonal"
 #endif
                             );
            if (ret < 0) {
@@ -5578,7 +5578,7 @@ int main(int argc, char **argv)
               dlev.diff==DIFF_IMPOSSIBLE ? "Impossible (no solution exists)":
               "INTERNAL ERROR: unrecognised difficulty code");
        if (p->killer)
-           printf("Killer diffculty: %s\n",
+           printf("Killer difficulty: %s\n",
                   dlev.kdiff==DIFF_KSINGLE ? "Trivial (single square cages only)":
                   dlev.kdiff==DIFF_KMINMAX ? "Simple (maximum sum analysis required)":
                   dlev.kdiff==DIFF_KSUMS ? "Intermediate (sum possibilities)":