Skip simulated moves that try to move exploding blocks

strategy.py

@@ -92,6 +92,15 @@ class State:
                 score += row - start_row + 1
         return score
 
+    def locked(self, i):
+        block = self.blocks[i]
+        if block == NOBLOCK:
+            return False
+        if is_basic(block):
+            return self.groupsizes[i] >= MIN_BASIC_GROUP_SIZE
+        assert is_bomb(block)
+        return self.groupsizes[i] >= MIN_BOMB_GROUP_SIZE
+
     def move(self, *moves):
         deep = any(move in (GRAB, DROP, SWAP) for move in moves)
         s = self.copy(deep)
@@ -112,14 +121,14 @@ class State:
                 row = s.colskip[s.exa]
                 assert row < s.nrows
                 i = row * COLUMNS + s.exa
+                if not s.locked(i):
                     s.held = s.blocks[i]
                     s.blocks[i] = NOBLOCK
                     s.colskip[s.exa] += 1
                     s.ungroup(i)
 
             elif move == DROP:
-                assert not s.colbusy(s.exa)
-                assert s.held != NOBLOCK
+                if s.held != NOBLOCK:
                     row = s.colskip[s.exa]
                     assert row > 0
                     i = (row - 1) * COLUMNS + s.exa
@@ -133,7 +142,7 @@ class State:
                 row = s.colskip[s.exa]
                 i = row * COLUMNS + s.exa
                 j = i + COLUMNS
-                assert j < len(s.blocks)
+                if j < len(s.blocks) and not s.locked(i) and not s.locked(j):
                     bi = s.blocks[i]
                     bj = s.blocks[j]
                     if bi != bj: