X-Git-Url: http://git.scottworley.com/planeteer/blobdiff_plain/5a1593ab8a31d024658664769920cbd0d5438e34..5f1a50e1c7d4ae2908197673d5dbf948b3509a8f:/planeteer.go

diff --git a/planeteer.go b/planeteer.go
index 87c7448..bc47c3d 100644
--- a/planeteer.go
+++ b/planeteer.go
@@ -26,21 +26,20 @@ var datafile = flag.String("planet_data_file", "planet-data",
 	"The file to read planet data from")
 
 type Commodity struct {
-	Name      string
 	BasePrice int
 	CanSell   bool
 	Limit     int
 }
-
+type Planet struct {
+	Name     string
+	BeaconOn bool
+	/* Use relative prices rather than absolute prices because you
+	   can get relative prices without traveling to each planet. */
+	RelativePrices map [string] int
+}
 type planet_data struct {
-	Commodities []Commodity
-	Planets []struct {
-		Name     string
-		BeaconOn bool
-		/* Use relative prices rather than absolute prices because you
-		   can get relative prices without traveling to each planet. */
-		RelativePrices map [string] int
-	}
+	Commodities map [string] Commodity
+	Planets []Planet
 }
 
 func ReadData() (data planet_data) {
@@ -56,44 +55,56 @@ func ReadData() (data planet_data) {
 	return
 }
 
+/* What is the value of hauling 'commodity' from 'from' to 'to'?
+ * Take into account the available funds and the available cargo space. */
 func TradeValue(data planet_data,
-                from_index, to_index, commodity_index, quantity int) int {
-
-	commodity := &data.Commodities[commodity_index]
-	if !commodity.CanSell {
+                from, to *Planet,
+                commodity string,
+                initial_funds, max_quantity int) int {
+	if !data.Commodities[commodity].CanSell {
 		return 0
 	}
-
-	from_planet := &data.Planets[from_index]
-	from_relative_price, from_available := from_planet.RelativePrices[commodity.Name]
+	from_relative_price, from_available := from.RelativePrices[commodity]
 	if !from_available {
 		return 0
 	}
-
-	to_planet := &data.Planets[to_index]
-	to_relative_price, to_available := to_planet.RelativePrices[commodity.Name]
+	to_relative_price, to_available := to.RelativePrices[commodity]
 	if !to_available {
 		return 0
 	}
 
-	from_absolute_price := from_relative_price * commodity.BasePrice
-	to_absolute_price := to_relative_price * commodity.BasePrice
+	base_price := data.Commodities[commodity].BasePrice
+	from_absolute_price := from_relative_price * base_price
+	to_absolute_price := to_relative_price * base_price
 	buy_price := from_absolute_price
 	sell_price := int(float64(to_absolute_price) * 0.9)
-	return (sell_price - buy_price) * quantity
-
+	var can_afford int = initial_funds / buy_price
+	quantity := can_afford
+	if quantity > max_quantity {
+		quantity = max_quantity
+	}
+	return (sell_price - buy_price) * max_quantity
 }
 
-func FindBestTrades(data planet_data) [][]*Commodity {
-	best := make([][]*Commodity, len(data.Planets))
-	for from_index := range data.Planets {
-		best[from_index] = make([]*Commodity, len(data.Planets))
-		for to_index := range data.Planets {
+func FindBestTrades(data planet_data) [][]string {
+	best := make([][]string, len(data.Planets))
+	for from_index, from_planet := range data.Planets {
+		best[from_index] = make([]string, len(data.Planets))
+		for to_index, to_planet := range data.Planets {
 			best_gain := 0
-			for commodity_index := range data.Commodities {
-				gain := TradeValue(data, from_index, to_index, commodity_index, 1)
+			price_list := from_planet.RelativePrices
+			if len(to_planet.RelativePrices) < len(from_planet.RelativePrices) {
+				price_list = to_planet.RelativePrices
+			}
+			for commodity := range price_list {
+				gain := TradeValue(data,
+				                   &from_planet,
+				                   &to_planet,
+				                   commodity,
+				                   10000000,
+				                   1)
 				if gain > best_gain {
-					best[from_index][to_index] = &data.Commodities[commodity_index]
+					best[from_index][to_index] = commodity
 					gain = best_gain
 				}
 			}
@@ -109,8 +120,8 @@ func main() {
 	for from_index, from_planet := range data.Planets {
 		for to_index, to_planet := range data.Planets {
 			best_trade := "(nothing)"
-			if best_trades[from_index][to_index] != nil {
-				best_trade = best_trades[from_index][to_index].Name
+			if best_trades[from_index][to_index] != "" {
+				best_trade = best_trades[from_index][to_index]
 			}
 			fmt.Printf("%s to %s: %s\n", from_planet.Name, to_planet.Name, best_trade)
 		}