1 files changed, 35 insertions, 48 deletions

diff --git a/src/solvers/h48/solve.h b/src/solvers/h48/solve.h
index 7430228..751df8f 100644
--- a/src/solvers/h48/solve.h
+++ b/src/solvers/h48/solve.h
@@ -11,10 +11,9 @@ typedef struct {
         uint32_t *cocsepdata;
         uint32_t *h48data;
         char **nextsol;
-        bool niss;
+        uint8_t nissbranch;
         int8_t npremoves;
         uint8_t premoves[MAXLEN];
-        int8_t totmoves;
 } dfsarg_solveh48_t;
 
 typedef struct {
@@ -65,37 +64,30 @@ _static_inline bool
 solve_h48_stop(dfsarg_solveh48_t *arg)
 {
         uint32_t data, data_inv;
-        int8_t bound, newbound;
-        bool niss = false;
+        int8_t bound;
 
+        arg->nissbranch = NONISS;
         bound = get_h48_cdata(arg->cube, arg->cocsepdata, &data);
-        if (bound + arg->totmoves > arg->depth)
+        if (bound + arg->nmoves + arg->npremoves > arg->depth)
                 return true;
 
-        newbound = get_h48_cdata(arg->inverse, arg->cocsepdata, &data_inv);
-        if (newbound + arg->totmoves > arg->depth)
+        bound = get_h48_cdata(arg->inverse, arg->cocsepdata, &data_inv);
+        if (bound + arg->nmoves + arg->npremoves > arg->depth)
                 return true;
-        if (newbound < bound) {
-                bound = newbound;
-                niss = true;
-        }
 
-        newbound = get_h48_bound(arg->cube, data, arg->h, arg->k, arg->h48data);
+        bound = get_h48_bound(arg->cube, data, arg->h, arg->k, arg->h48data);
         // LOG("Using pval %" PRId8 "\n", bound);
-        if (newbound + arg->totmoves > arg->depth)
+        if (bound + arg->nmoves + arg->npremoves > arg->depth)
                 return true;
-        if (newbound < bound) {
-                bound = newbound;
-                niss = false;
-        }
-        newbound = get_h48_bound(arg->inverse, data_inv, arg->h, arg->k, arg->h48data);
-        if (newbound + arg->totmoves > arg->depth)
+        if (bound + arg->nmoves + arg->npremoves == arg->depth)
+                arg->nissbranch = INVERSEBRANCH;
+
+        bound = get_h48_bound(arg->inverse, data_inv, arg->h, arg->k, arg->h48data);
+        if (bound + arg->nmoves + arg->npremoves > arg->depth)
                 return true;
-        if (newbound < bound) {
-                bound = newbound;
-                niss = true;
-        }
-        arg->niss = niss;
+        if (bound + arg->nmoves + arg->npremoves == arg->depth)
+                arg->nissbranch = BRANCH;
+
         return false;
 }
 
@@ -113,7 +105,7 @@ solve_h48_dfs(dfsarg_solveh48_t *arg)
                 return 0;
 
         if (issolved(arg->cube)) {
-                if (arg->totmoves != arg->depth)
+                if (arg->nmoves + arg->npremoves != arg->depth)
                         return 0;
                 solve_h48_appendsolution(arg);
                 return 1;
@@ -122,34 +114,28 @@ solve_h48_dfs(dfsarg_solveh48_t *arg)
         /* TODO: avoid copy, change arg and undo changes after recursion */
         nextarg = *arg;
         ret = 0;
-        nextarg.totmoves = arg->totmoves + 1;
-        if(arg->niss) {
-                nextarg.npremoves = arg->npremoves + 1;
+        uint32_t allowed;
+        if(arg->nissbranch & 0x01) {
+                allowed = allowednextmoveH48(arg->premoves, arg->npremoves, arg->nissbranch);
                 for (m = 0; m < 18; m++) {
-                        nextarg.premoves[arg->npremoves] = m;
-                if (!allowednextmove(nextarg.premoves, nextarg.npremoves)) {
-                        /* If a move is not allowed, neither are its 180
-                         * and 270 degree variations */
-                        m += 2;
-                        continue;
-                }
-                nextarg.cube = premove(arg->cube, m);
-                nextarg.inverse = move(arg->inverse, m);
-                ret += solve_h48_dfs(&nextarg);
+                        if(allowed & (1 << m)) {
+                                nextarg.npremoves = arg->npremoves + 1;
+                                nextarg.premoves[arg->npremoves] = m;
+                                nextarg.inverse = move(arg->inverse, m);
+                                nextarg.cube = premove(arg->cube, m);
+                                ret += solve_h48_dfs(&nextarg);
+                        }
                 }
         } else {
-                nextarg.nmoves = arg->nmoves + 1;
+                allowed = allowednextmoveH48(arg->moves, arg->nmoves, arg->nissbranch);
                 for (m = 0; m < 18; m++) {
-                        nextarg.moves[arg->nmoves] = m;
-                        if (!allowednextmove(nextarg.moves, nextarg.nmoves)) {
-                                /* If a move is not allowed, neither are its 180
-                                * and 270 degree variations */
-                                m += 2;
-                                continue;
+                        if (allowed & (1 << m)) {
+                                nextarg.nmoves = arg->nmoves + 1;
+                                nextarg.moves[arg->nmoves] = m;
+                                nextarg.cube = move(arg->cube, m);
+                                nextarg.inverse = premove(arg->inverse, m);
+                                ret += solve_h48_dfs(&nextarg);
                         }
-                        nextarg.cube = move(arg->cube, m);
-                        nextarg.inverse = premove(arg->inverse, m);
-                        ret += solve_h48_dfs(&nextarg);
                 }
         }
 
@@ -192,6 +178,7 @@ solve_h48(
                 LOG("Found %" PRId64 " solutions, searching at depth %"
                     PRId8 "\n", nsols, arg.depth);
                 arg.nmoves = 0;
+                arg.npremoves = 0;
                 solve_h48_dfs(&arg);
         }