1 files changed, 30 insertions, 21 deletions

diff --git a/19.c b/19.c
index a53f3d3..f7c950e 100644
--- a/19.c
+++ b/19.c
@@ -45,7 +45,6 @@ blueprint_ctor(struct blueprint * b, int id, int ore_ore, int clay_ore,
 struct material {
 	long amount;
 	long robots;
-	long pending;
 };
 
 
@@ -54,7 +53,6 @@ material_ctor(struct material * m, long amount, long robots)
 {
 	m->amount = amount;
 	m->robots = robots;
-	m->pending = 0;
 }
 
 
@@ -63,11 +61,11 @@ material_ctor(struct material * m, long amount, long robots)
 // Amount increases by the number of robots
 // Number of robots increases by number of pending robots
 void
-material_tick(struct material * m)
+material_tick(struct material * m, int build)
 {
 	m->amount += m->robots;
-	m->robots += m->pending;
-	m->pending = 0;
+	if (build)
+		++m->robots;
 }
 
 
@@ -76,6 +74,7 @@ struct inventory {
 	struct material clay;
 	struct material bsdn;
 	struct material geod;
+	enum MATERIAL pending;
 };
 
 
@@ -86,6 +85,7 @@ inventory_init(struct inventory * i)
 	material_ctor(&i->clay, 0, 0);
 	material_ctor(&i->bsdn, 0, 0);
 	material_ctor(&i->geod, 0, 0);
+	i->pending = -1;
 }
 
 
@@ -113,10 +113,11 @@ inventory_cmp(struct inventory const * a, struct inventory const * b)
 void
 inventory_tick(struct inventory * i)
 {
-	material_tick(&i->ore);
-	material_tick(&i->clay);
-	material_tick(&i->bsdn);
-	material_tick(&i->geod);
+	material_tick(&i->ore, i->pending == ORE);
+	material_tick(&i->clay, i->pending == CLAY);
+	material_tick(&i->bsdn, i->pending == BSDN);
+	material_tick(&i->geod, i->pending == GEOD);
+	i->pending = -1;
 }
 
 
@@ -126,35 +127,39 @@ inventory_build(struct inventory * i, struct blueprint const * b, enum MATERIAL
 {
 	switch (m) {
 	case ORE:
-		if (i->ore.amount < b->ore_ore)
+		if (i->pending != -1
+				|| i->ore.amount < b->ore_ore)
 			return -1;
 		i->ore.amount -= b->ore_ore;
-		i->ore.pending += 1;
+		i->pending = ORE;
 		break;
 
 	case CLAY:
-		if (i->ore.amount < b->clay_ore)
+		if (i->pending != -1
+				|| i->ore.amount < b->clay_ore)
 			return -1;
 		i->ore.amount -= b->clay_ore;
-		i->clay.pending += 1;
+		i->pending = CLAY;
 		break;
 
 	case BSDN:
-		if (i->ore.amount < b->bsdn_ore
+		if (i->pending != -1
+				|| i->ore.amount < b->bsdn_ore
 				|| i->clay.amount < b->bsdn_clay)
 			return -1;
 		i->ore.amount -= b->bsdn_ore;
 		i->clay.amount -= b->bsdn_clay;
-		i->bsdn.pending += 1;
+		i->pending = BSDN;
 		break;
 
 	case GEOD:
-		if (i->ore.amount < b->geod_ore
+		if (i->pending != -1
+				|| i->ore.amount < b->geod_ore
 				|| i->bsdn.amount < b->geod_bsdn)
 			return -1;
 		i->ore.amount -= b->geod_ore;
 		i->bsdn.amount -= b->geod_bsdn;
-		i->geod.pending += 1;
+		i->pending = GEOD;
 		break;
 
 	default:
@@ -224,7 +229,8 @@ inventory_build_exhaustive(struct inventory * i, struct blueprint const * b, int
 	// Try building a geode robot, and check if that's better than doing nothing.
 	if (inventory_build(&test, b, GEOD) == 0) {
 //		fprintf(stderr, "%d: building a geod robot (%ld)\n", remaining, test.geod.amount);
-		inventory_build_exhaustive(&test, b, remaining);
+		inventory_tick(&test);
+		inventory_build_exhaustive(&test, b, remaining - 1);
 		if (inventory_cmp(&test, &best) > 0)
 			best = test;
 		test = *i;
@@ -233,7 +239,8 @@ inventory_build_exhaustive(struct inventory * i, struct blueprint const * b, int
 	// Try building a obsidian robot, and checking if that's better than anything else
 	if (inventory_build(&test, b, BSDN) == 0) {
 //		fprintf(stderr, "%d: building a bsdn robot (%ld)\n", remaining, test.bsdn.amount);
-		inventory_build_exhaustive(&test, b, remaining);
+		inventory_tick(&test);
+		inventory_build_exhaustive(&test, b, remaining - 1);
 		if (inventory_cmp(&test, &best) > 0)
 			best = test;
 		test = *i;
@@ -242,7 +249,8 @@ inventory_build_exhaustive(struct inventory * i, struct blueprint const * b, int
 	// Try building a clay robot, and checking if that's better than anything else
 	if (inventory_build(&test, b, CLAY) == 0) {
 //		fprintf(stderr, "%d: building a clay robot (%ld)\n", remaining, test.clay.amount);
-		inventory_build_exhaustive(&test, b, remaining);
+		inventory_tick(&test);
+		inventory_build_exhaustive(&test, b, remaining - 1);
 		if (inventory_cmp(&test, &best) > 0)
 			best = test;
 		test = *i;
@@ -251,7 +259,8 @@ inventory_build_exhaustive(struct inventory * i, struct blueprint const * b, int
 	// Try building a ore robot, and checking if that's better than anything else
 	if (inventory_build(&test, b, ORE) == 0) {
 //		fprintf(stderr, "%d: building a ore robot (%ld)\n", remaining, test.ore.amount);
-		inventory_build_exhaustive(&test, b, remaining);
+		inventory_tick(&test);
+		inventory_build_exhaustive(&test, b, remaining - 1);
 		if (inventory_cmp(&test, &best) > 0)
 			best = test;
 		test = *i;