]> git.scottworley.com Git - planeteer/blobdiff - planeteer.go
Performance!
[planeteer] / planeteer.go
index a07c6693d3bc2b4fc6af15a8c89af200b788e848..5e406fab68fde9a6823e4a9efe16355b60422780 100644 (file)
@@ -21,21 +21,27 @@ import "flag"
 import "fmt"
 import "json"
 import "os"
+import "runtime/pprof"
 import "strings"
 
+var funds = flag.Int("funds", 0,
+       "Starting funds")
+
 var start = flag.String("start", "",
        "The planet to start at")
 
-var end = flag.String("end", "",
-       "A comma-separated list of planets to end at")
+var flight_plan_string = flag.String("flight_plan", "",
+       "Your hyper-holes for the day, comma-separated.")
+
+var end_string = flag.String("end", "",
+       "A comma-separated list of acceptable ending planets.")
 
 var planet_data_file = flag.String("planet_data_file", "planet-data",
        "The file to read planet data from")
 
-var fuel = flag.Int("fuel", 16,
-       "Reactor units; How many non-Eden jumps we can make "+
-               "(but remember that deviating from the flight plan "+
-               "costs two units of fuel per jump)")
+var fuel = flag.Int("fuel", 16, "Hyper Jump power left")
+
+var hold = flag.Int("hold", 300, "Size of your cargo hold")
 
 var start_edens = flag.Int("start_edens", 0,
        "How many Eden Warp Units are you starting with?")
@@ -46,17 +52,55 @@ var end_edens = flag.Int("end_edens", 0,
 var cloak = flag.Bool("cloak", false,
        "Make sure to end with a Device of Cloaking")
 
-var drones = flag.Int("drones", 0,
-       "Buy this many Fighter Drones")
+var drones = flag.Int("drones", 0, "Buy this many Fighter Drones")
+
+var batteries = flag.Int("batteries", 0, "Buy this many Shield Batterys")
+
+var drone_price = flag.Int("drone_price", 0, "Today's Fighter Drone price")
 
-var batteries = flag.Int("batteries", 0,
-       "Buy this many Shield Batterys")
+var battery_price = flag.Int("battery_price", 0, "Today's Shield Battery price")
 
 var visit_string = flag.String("visit", "",
        "A comma-separated list of planets to make sure to visit")
 
+var cpuprofile = flag.String("cpuprofile", "", "write cpu profile to file")
+
+
+var visit_cache []string
 func visit() []string {
-       return strings.Split(*visit_string, ",")
+       if visit_cache == nil {
+               if *visit_string == "" {
+                       return nil
+               }
+               visit_cache = strings.Split(*visit_string, ",")
+       }
+       return visit_cache
+}
+
+var flight_plan_cache []string
+func flight_plan() []string {
+       if flight_plan_cache == nil {
+               if *flight_plan_string == "" {
+                       return nil
+               }
+               flight_plan_cache = strings.Split(*flight_plan_string, ",")
+       }
+       return flight_plan_cache
+}
+
+var end_cache map[string]bool
+func end() map[string]bool {
+       if end_cache == nil {
+               if *end_string == "" {
+                       return nil
+               }
+               m := make(map[string]bool)
+               for _, p := range strings.Split(*end_string, ",") {
+                       m[p] = true
+               }
+               end_cache = m
+       }
+       return end_cache
 }
 
 type Commodity struct {
@@ -73,7 +117,8 @@ type Planet struct {
 type planet_data struct {
        Commodities map[string]Commodity
        Planets     map[string]Planet
-       pi, ci      map[string]int // Generated; not read from file
+       p2i, c2i    map[string]int // Generated; not read from file
+       i2p, i2c    []string       // Generated; not read from file
 }
 
 func ReadData() (data planet_data) {
@@ -107,19 +152,39 @@ func ReadData() (data planet_data) {
  * Note that the sizes of each dimension are data driven.  Many dimensions
  * collapse to one possible value (ie, disappear) if the corresponding
  * feature is not enabled.
+ *
+ * The order of the dimensions in the list of constants below determines
+ * their layout in RAM.  The cargo-based 'dimensions' are not completely
+ * independent -- some combinations are illegal and not used.  They are
+ * handled as three dimensions rather than one for simplicity.  Placing
+ * these dimensions first causes the unused cells in the table to be
+ * grouped together in large blocks.  This keeps them from polluting
+ * cache lines, and if they are large enough, prevent the memory manager
+ * from allocating pages for these areas at all.
+ *
+ * If the table gets too big to fit in RAM:
+ *    * Combine the Edens, Cloaks, and UnusedCargo dimensions.  Of the
+ *      24 combinations, only 15 are legal: a 38% savings.
+ *    * Reduce the size of the Fuel dimension to 3.  We only ever look
+ *      backwards 2 units, so just rotate the logical values through
+ *      the same 3 physical addresses.  This is good for an 82% savings.
+ *    * Reduce the size of the Edens dimension from 3 to 2, for the
+ *      same reasons as Fuel above.  33% savings.
+ *    * Buy more ram.  (Just sayin'.  It's cheaper than you think.)
+ *      
  */
 
 // The official list of dimensions:
 const (
-       // Name          Num  Size  Description
+       // Name                Num  Size  Description
        Edens        = iota //   1     3  # of Eden warp units (0 - 2 typically)
        Cloaks              //   2     2  # of Devices of Cloaking (0 or 1)
        UnusedCargo         //   3     4  # of unused cargo spaces (0 - 3 typically)
-       Fuel                //   4    17  Reactor power left (0 - 16)
+       Fuel                //   4    17  Hyper jump power left (0 - 16)
        Location            //   5    26  Location (which planet)
        Hold                //   6    15  Cargo bay contents (a *Commodity or nil)
-       NeedFighters        //   7     2  Errand: Buy fighter drones (needed or not)
-       NeedShields         //   8     2  Errand: Buy shield batteries (needed or not)
+       BuyFighters         //   7     2  Errand: Buy fighter drones
+       BuyShields          //   8     2  Errand: Buy shield batteries
        Visit               //   9  2**N  Visit: Stop by these N planets in the route
 
        NumDimensions
@@ -134,51 +199,59 @@ func bint(b bool) int {
 
 func DimensionSizes(data planet_data) []int {
        eden_capacity := data.Commodities["Eden Warp Units"].Limit
+       if *start_edens > eden_capacity {
+               eden_capacity = *start_edens
+       }
        cloak_capacity := bint(*cloak)
-       dims := []int{
-               eden_capacity + 1,
-               cloak_capacity + 1,
-               eden_capacity + cloak_capacity + 1,
-               *fuel + 1,
-               len(data.Planets),
-               len(data.Commodities),
-               bint(*drones > 0) + 1,
-               bint(*batteries > 0) + 1,
-               1 << uint(len(visit())),
-       }
-       if len(dims) != NumDimensions {
-               panic("Dimensionality mismatch")
+       dims := make([]int, NumDimensions)
+       dims[Edens] = eden_capacity + 1
+       dims[Cloaks] = cloak_capacity + 1
+       dims[UnusedCargo] = eden_capacity + cloak_capacity + 1
+       dims[Fuel] = *fuel + 1
+       dims[Location] = len(data.Planets)
+       dims[Hold] = len(data.Commodities) + 1
+       dims[BuyFighters] = bint(*drones > 0) + 1
+       dims[BuyShields] = bint(*batteries > 0) + 1
+       dims[Visit] = 1 << uint(len(visit()))
+
+       // Remind myself to add a line above when adding new dimensions
+       for i, dim := range dims {
+               if dim < 1 {
+                       panic(i)
+               }
        }
        return dims
 }
 
 func StateTableSize(dims []int) int {
-       sum := 0
+       product := 1
        for _, size := range dims {
-               sum += size
+               product *= size
        }
-       return sum
+       return product
 }
 
 type State struct {
-       funds, from int
-}
-
-func NewStateTable(dims []int) []State {
-       return make([]State, StateTableSize(dims))
+       value, from int
 }
 
 func EncodeIndex(dims, addr []int) int {
        index := addr[0]
-       for i := 1; i < len(dims); i++ {
+       if addr[0] > dims[0] {
+               panic(0)
+       }
+       for i := 1; i < NumDimensions; i++ {
+               if addr[i] < 0 || addr[i] > dims[i] {
+                       panic(i)
+               }
                index = index*dims[i] + addr[i]
        }
        return index
 }
 
 func DecodeIndex(dims []int, index int) []int {
-       addr := make([]int, len(dims))
-       for i := len(dims) - 1; i > 0; i-- {
+       addr := make([]int, NumDimensions)
+       for i := NumDimensions - 1; i > 0; i-- {
                addr[i] = index % dims[i]
                index /= dims[i]
        }
@@ -186,102 +259,458 @@ func DecodeIndex(dims []int, index int) []int {
        return addr
 }
 
-/* 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, to Planet,
-commodity string,
-initial_funds, max_quantity int) int {
-       if !data.Commodities[commodity].CanSell {
-               return 0
+func InitializeStateTable(data planet_data, dims []int) []State {
+       table := make([]State, StateTableSize(dims))
+
+       addr := make([]int, NumDimensions)
+       addr[Fuel] = *fuel
+       addr[Edens] = *start_edens
+       addr[Location] = data.p2i[*start]
+       table[EncodeIndex(dims, addr)].value = *funds
+
+       return table
+}
+
+/* These four fill procedures fill in the cell at address addr by
+ * looking at all the possible ways to reach this cell and selecting
+ * the best one.
+ *
+ * The other obvious implementation choice is to do this the other way
+ * around -- for each cell, conditionally overwrite all the other cells
+ * that are reachable *from* the considered cell.  We choose gathering
+ * reads over scattering writes to avoid having to take a bunch of locks.
+ */
+
+func UpdateCell(table []State, here, there, value_difference int) {
+       possible_value := table[there].value + value_difference
+       if table[there].value > 0 && possible_value > table[here].value {
+               table[here].value = possible_value
+               table[here].from = there
        }
-       from_relative_price, from_available := from.RelativePrices[commodity]
-       if !from_available {
-               return 0
+}
+
+func FillCellByArriving(data planet_data, dims []int, table []State, addr []int) {
+       my_index := EncodeIndex(dims, addr)
+       other := make([]int, NumDimensions)
+       copy(other, addr)
+
+       /* Travel here via a 2-fuel unit jump */
+       if addr[Fuel]+2 < dims[Fuel] {
+               other[Fuel] = addr[Fuel] + 2
+               for other[Location] = 0; other[Location] < dims[Location]; other[Location]++ {
+                       if data.Planets[data.i2p[addr[Location]]].BeaconOn {
+                               UpdateCell(table, my_index, EncodeIndex(dims, other), 0)
+                       }
+               }
+               other[Location] = addr[Location]
+               other[Fuel] = addr[Fuel]
        }
-       to_relative_price, to_available := to.RelativePrices[commodity]
-       if !to_available {
-               return 0
+
+       /* Travel here via a hyper hole */
+       if addr[Fuel]+1 < dims[Fuel] {
+               hole_index := (dims[Fuel] - 1) - (addr[Fuel] + 1)
+               if hole_index < len(flight_plan()) && addr[Location] == data.p2i[flight_plan()[hole_index]] {
+                       other[Fuel] = addr[Fuel] + 1
+                       for other[Location] = 0; other[Location] < dims[Location]; other[Location]++ {
+                               UpdateCell(table, my_index, EncodeIndex(dims, other), 0)
+                       }
+                       other[Location] = addr[Location]
+                       other[Fuel] = addr[Fuel]
+               }
        }
 
+       /* Travel here via Eden Warp Unit */
+       if addr[Edens]+1 < dims[Edens] && addr[UnusedCargo] > 1 {
+               _, available := data.Planets[data.i2p[addr[Location]]].RelativePrices["Eden Warp Units"]
+               if !available {
+                       other[Edens] = addr[Edens] + 1
+                       other[UnusedCargo] = addr[UnusedCargo] - 1
+                       for other[Location] = 0; other[Location] < dims[Location]; other[Location]++ {
+                               UpdateCell(table, my_index, EncodeIndex(dims, other), 0)
+                       }
+                       other[Location] = addr[Location]
+                       other[UnusedCargo] = addr[UnusedCargo]
+                       other[Edens] = addr[Edens]
+               }
+       }
+}
+
+func FillCellBySelling(data planet_data, dims []int, table []State, addr []int) {
+       if addr[Hold] > 0 {
+               // Can't sell and still have cargo
+               return
+       }
+       if addr[UnusedCargo] > 0 {
+               // Can't sell everything and still have 'unused' holds
+               return
+       }
+       my_index := EncodeIndex(dims, addr)
+       other := make([]int, NumDimensions)
+       copy(other, addr)
+       planet := data.i2p[addr[Location]]
+       for other[Hold] = 0; other[Hold] < dims[Hold]; other[Hold]++ {
+               commodity := data.i2c[other[Hold]]
+               if !data.Commodities[commodity].CanSell {
+                       // TODO: Dump cargo
+                       continue
+               }
+               relative_price, available := data.Planets[planet].RelativePrices[commodity]
+               if !available {
+                       continue
+               }
+               base_price := data.Commodities[commodity].BasePrice
+               absolute_price := float64(base_price) * float64(relative_price) / 100.0
+               sell_price := int(absolute_price * 0.9)
+
+               for other[UnusedCargo] = 0; other[UnusedCargo] < dims[UnusedCargo]; other[UnusedCargo]++ {
+
+                       quantity := *hold - (other[UnusedCargo] + other[Cloaks] + other[Edens])
+                       sale_value := quantity * sell_price
+                       UpdateCell(table, my_index, EncodeIndex(dims, other), sale_value)
+               }
+       }
+       other[UnusedCargo] = addr[UnusedCargo]
+}
+
+func FillCellByBuying(data planet_data, dims []int, table []State, addr []int) {
+       if addr[Hold] == 0 {
+               // Can't buy and then have nothing
+               return
+       }
+       my_index := EncodeIndex(dims, addr)
+       other := make([]int, NumDimensions)
+       copy(other, addr)
+       planet := data.i2p[addr[Location]]
+       commodity := data.i2c[addr[Hold]]
+       if !data.Commodities[commodity].CanSell {
+               return
+       }
+       relative_price, available := data.Planets[planet].RelativePrices[commodity]
+       if !available {
+               return
+       }
        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)
-       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
+       absolute_price := int(float64(base_price) * float64(relative_price) / 100.0)
+       quantity := *hold - (addr[UnusedCargo] + addr[Cloaks] + addr[Edens])
+       total_price := quantity * absolute_price
+       other[Hold] = 0
+       other[UnusedCargo] = 0
+       UpdateCell(table, my_index, EncodeIndex(dims, other), -total_price)
+       other[UnusedCargo] = addr[UnusedCargo]
+       other[Hold] = addr[Hold]
 }
 
-func FindBestTrades(data planet_data) [][]string {
-       // TODO: We can't cache this because this can change based on available funds.
-       best := make([][]string, len(data.Planets))
-       for from := range data.Planets {
-               best[data.pi[from]] = make([]string, len(data.Planets))
-               for to := range data.Planets {
-                       best_gain := 0
-                       price_list := data.Planets[from].RelativePrices
-                       if len(data.Planets[to].RelativePrices) < len(data.Planets[from].RelativePrices) {
-                               price_list = data.Planets[to].RelativePrices
+func FillCellByMisc(data planet_data, dims []int, table []State, addr []int) {
+       my_index := EncodeIndex(dims, addr)
+       other := make([]int, NumDimensions)
+       copy(other, addr)
+
+       /* Buy a Device of Cloaking */
+       if addr[Cloaks] == 1 && addr[UnusedCargo] < dims[UnusedCargo]-1 {
+               relative_price, available := data.Planets[data.i2p[addr[Location]]].RelativePrices["Device Of Cloakings"]
+               if available {
+                       absolute_price := int(float64(data.Commodities["Device Of Cloakings"].BasePrice) * float64(relative_price) / 100.0)
+                       other[Cloaks] = 0
+                       if other[Hold] != 0 {
+                               other[UnusedCargo] = addr[UnusedCargo] + 1
                        }
-                       for commodity := range price_list {
-                               gain := TradeValue(data,
-                                       data.Planets[from],
-                                       data.Planets[to],
-                                       commodity,
-                                       10000000,
-                                       1)
-                               if gain > best_gain {
-                                       best[data.pi[from]][data.pi[to]] = commodity
-                                       gain = best_gain
+                       UpdateCell(table, my_index, EncodeIndex(dims, other), -absolute_price)
+                       other[UnusedCargo] = addr[UnusedCargo]
+                       other[Cloaks] = addr[Cloaks]
+               }
+       }
+
+       /* Silly: Dump a Device of Cloaking */
+
+       /* Buy Fighter Drones */
+       if addr[BuyFighters] == 1 {
+               relative_price, available := data.Planets[data.i2p[addr[Location]]].RelativePrices["Fighter Drones"]
+               if available {
+                       absolute_price := int(float64(data.Commodities["Fighter Drones"].BasePrice) * float64(relative_price) / 100.0)
+                       other[BuyFighters] = 0
+                       UpdateCell(table, my_index, EncodeIndex(dims, other), -absolute_price * *drones)
+                       other[BuyFighters] = addr[BuyFighters]
+               }
+       }
+
+       /* Buy Shield Batteries */
+       if addr[BuyShields] == 1 {
+               relative_price, available := data.Planets[data.i2p[addr[Location]]].RelativePrices["Shield Batterys"]
+               if available {
+                       absolute_price := int(float64(data.Commodities["Shield Batterys"].BasePrice) * float64(relative_price) / 100.0)
+                       other[BuyShields] = 0
+                       UpdateCell(table, my_index, EncodeIndex(dims, other), -absolute_price * *batteries)
+                       other[BuyShields] = addr[BuyShields]
+               }
+       }
+
+       /* Visit this planet */
+       var i uint
+       for i = 0; i < uint(len(visit())); i++ {
+               if addr[Visit] & (1 << i) != 0 && visit()[i] == data.i2p[addr[Location]] {
+                       other[Visit] = addr[Visit] & ^(1 << i)
+                       UpdateCell(table, my_index, EncodeIndex(dims, other), 0)
+               }
+       }
+       other[Visit] = addr[Visit]
+
+}
+
+func FillCellByBuyingEdens(data planet_data, dims []int, table []State, addr []int) {
+       my_index := EncodeIndex(dims, addr)
+       other := make([]int, NumDimensions)
+       copy(other, addr)
+
+       /* Buy Eden warp units */
+       eden_limit := data.Commodities["Eden Warp Units"].Limit
+       if addr[Edens] > 0 && addr[Edens] <= eden_limit {
+               relative_price, available := data.Planets[data.i2p[addr[Location]]].RelativePrices["Eden Warp Units"]
+               if available {
+                       absolute_price := int(float64(data.Commodities["Eden Warp Units"].BasePrice) * float64(relative_price) / 100.0)
+                       for quantity := addr[Edens]; quantity > 0; quantity-- {
+                               other[Edens] = addr[Edens] - quantity
+                               if addr[Hold] != 0 {
+                                       other[UnusedCargo] = addr[UnusedCargo] + quantity
+                               }
+                               if other[UnusedCargo] < dims[UnusedCargo] {
+                                       UpdateCell(table, my_index, EncodeIndex(dims, other), -absolute_price * quantity)
                                }
                        }
+                       other[Edens] = addr[Edens]
+                       other[UnusedCargo] = addr[UnusedCargo]
+               }
+       }
+}
+
+func FillStateTable2Iteration(data planet_data, dims []int, table []State,
+addr []int, f func(planet_data, []int, []State, []int)) {
+       /* TODO: Justify the safety of the combination of this dimension
+        * iteration and the various phases f.  */
+       for addr[Hold] = 0; addr[Hold] < dims[Hold]; addr[Hold]++ {
+               for addr[Cloaks] = 0; addr[Cloaks] < dims[Cloaks]; addr[Cloaks]++ {
+                       for addr[UnusedCargo] = 0; addr[UnusedCargo] < dims[UnusedCargo]; addr[UnusedCargo]++ {
+                               for addr[BuyFighters] = 0; addr[BuyFighters] < dims[BuyFighters]; addr[BuyFighters]++ {
+                                       for addr[BuyShields] = 0; addr[BuyShields] < dims[BuyShields]; addr[BuyShields]++ {
+                                               for addr[Visit] = 0; addr[Visit] < dims[Visit]; addr[Visit]++ {
+                                                       f(data, dims, table, addr)
+                                               }
+                                       }
+                               }
+                       }
+               }
+       }
+}
+
+func FillStateTable2(data planet_data, dims []int, table []State,
+addr []int, barrier chan<- bool) {
+       FillStateTable2Iteration(data, dims, table, addr, FillCellByArriving)
+       FillStateTable2Iteration(data, dims, table, addr, FillCellBySelling)
+       FillStateTable2Iteration(data, dims, table, addr, FillCellByBuying)
+       FillStateTable2Iteration(data, dims, table, addr, FillCellByMisc)
+       FillStateTable2Iteration(data, dims, table, addr, FillCellByBuyingEdens)
+       if barrier != nil {
+               barrier <- true
+       }
+}
+
+/* Filling the state table is a set of nested for loops NumDimensions deep.
+ * We split this into two procedures: 1 and 2.  #1 is the outer, slowest-
+ * changing indexes.  #1 fires off many calls to #2 that run in parallel.
+ * The order of the nesting of the dimensions, the order of iteration within
+ * each dimension, and where the 1 / 2 split is placed are carefully chosen 
+ * to make this arrangement safe.
+ *
+ * Outermost two layers: Go from high-energy states (lots of fuel, edens) to
+ * low-energy state.  These must be processed sequentially and in this order
+ * because you travel through high-energy states to get to the low-energy
+ * states.
+ *
+ * Third layer: Planet.  This is a good layer to parallelize on.  There's
+ * high enough cardinality that we don't have to mess with parallelizing
+ * multiple layers for good utilization (on 2011 machines).  Each thread
+ * works on one planet's states and need not synchronize with peer threads.
+ */
+func FillStateTable1(data planet_data, dims []int, table []State) {
+       barrier := make(chan bool, len(data.Planets))
+       eden_capacity := data.Commodities["Eden Warp Units"].Limit
+       work_units := (float64(*fuel) + 1) * (float64(eden_capacity) + 1)
+       work_done := 0.0
+       for fuel_remaining := *fuel; fuel_remaining >= 0; fuel_remaining-- {
+               /* Make an Eden-buying pass (Eden vendors' energy gradient
+                * along the Edens dimension runs backwards) */
+               for edens_remaining := 0; edens_remaining <= eden_capacity; edens_remaining++ {
+                       for planet := range data.Planets {
+                               if _, available := data.Planets[planet].RelativePrices["Eden Warp Units"]; available {
+                                       addr := make([]int, len(dims))
+                                       addr[Edens] = edens_remaining
+                                       addr[Fuel] = fuel_remaining
+                                       addr[Location] = data.p2i[planet]
+                                       FillStateTable2(data, dims, table, addr, nil)
+                               }
+                       }
+               }
+               for edens_remaining := eden_capacity; edens_remaining >= 0; edens_remaining-- {
+                       /* Do the brunt of the work */
+                       for planet := range data.Planets {
+                               addr := make([]int, len(dims))
+                               addr[Edens] = edens_remaining
+                               addr[Fuel] = fuel_remaining
+                               addr[Location] = data.p2i[planet]
+                               go FillStateTable2(data, dims, table, addr, barrier)
+                       }
+                       for _ = range data.Planets {
+                               <-barrier
+                       }
+                       work_done++
+                       print(fmt.Sprintf("\r%3.0f%%", 100*work_done/work_units))
                }
        }
-       return best
+       print("\n")
+}
+
+func FindBestState(data planet_data, dims []int, table []State) int {
+       addr := make([]int, NumDimensions)
+       addr[Edens] = *end_edens
+       addr[Cloaks] = dims[Cloaks] - 1
+       addr[BuyFighters] = dims[BuyFighters] - 1
+       addr[BuyShields] = dims[BuyShields] - 1
+       addr[Visit] = dims[Visit] - 1
+       // Fuel, Hold, UnusedCargo left at 0
+       max_index := -1
+       max_value := 0
+       for addr[Location] = 0; addr[Location] < dims[Location]; addr[Location]++ {
+               if len(end()) == 0 || end()[data.i2p[addr[Location]]] {
+                       index := EncodeIndex(dims, addr)
+                       if table[index].value > max_value {
+                               max_value = table[index].value
+                               max_index = index
+                       }
+               }
+       }
+       return max_index
+}
+
+func Commas(n int) (s string) {
+       r := n % 1000
+       n /= 1000
+       for n > 0 {
+               s = fmt.Sprintf(",%03d", r) + s
+               r = n % 1000
+               n /= 1000
+       }
+       s = fmt.Sprint(r) + s
+       return
+}
+
+func DescribePath(data planet_data, dims []int, table []State, start int) (description []string) {
+       for index := start; index > 0 && table[index].from > 0; index = table[index].from {
+               var line string
+               addr := DecodeIndex(dims, index)
+               prev := DecodeIndex(dims, table[index].from)
+               if addr[Fuel] != prev[Fuel] {
+                       from := data.i2p[prev[Location]]
+                       to := data.i2p[addr[Location]]
+                       line += fmt.Sprintf("Jump from %v to %v (%v hyper jump units)", from, to, prev[Fuel]-addr[Fuel])
+               }
+               if addr[Edens] == prev[Edens] - 1 {
+                       from := data.i2p[prev[Location]]
+                       to := data.i2p[addr[Location]]
+                       line += fmt.Sprintf("Eden warp from %v to %v", from, to)
+               }
+               if addr[Hold] != prev[Hold] {
+                       if addr[Hold] == 0 {
+                               quantity := *hold - (prev[UnusedCargo] + prev[Edens] + prev[Cloaks])
+                               line += fmt.Sprintf("Sell %v %v", quantity, data.i2c[prev[Hold]])
+                       } else if prev[Hold] == 0 {
+                               quantity := *hold - (addr[UnusedCargo] + addr[Edens] + addr[Cloaks])
+                               line += fmt.Sprintf("Buy %v %v", quantity, data.i2c[addr[Hold]])
+                       } else {
+                               panic("Switched cargo?")
+                       }
+
+               }
+               if addr[Cloaks] == 1 && prev[Cloaks] == 0 {
+                       // TODO: Dump cloaks, convert from cargo?
+                       line += "Buy a Cloak"
+               }
+               if addr[Edens] > prev[Edens] {
+                       line += fmt.Sprint("Buy ", addr[Edens] - prev[Edens], " Eden Warp Units")
+               }
+               if addr[BuyShields] == 1 && prev[BuyShields] == 0 {
+                       line += fmt.Sprint("Buy ", *batteries, " Shield Batterys")
+               }
+               if addr[BuyFighters] == 1 && prev[BuyFighters] == 0 {
+                       line += fmt.Sprint("Buy ", *drones, " Fighter Drones")
+               }
+               if addr[Visit] != prev[Visit] {
+                       // TODO: verify that the bit chat changed is addr[Location]
+                       line += fmt.Sprint("Visit ", data.i2p[addr[Location]])
+               }
+               if line == "" {
+                       line = fmt.Sprint(prev, " -> ", addr)
+               }
+               description = append(description, fmt.Sprintf("%13v ", Commas(table[index].value)) + line)
+       }
+       return
 }
 
 // (Example of a use case for generics in Go)
-func IndexPlanets(m *map[string]Planet) map[string]int {
-       index := make(map[string]int, len(*m))
-       i := 0
+func IndexPlanets(m *map[string]Planet, start_at int) (map[string]int, []string) {
+       e2i := make(map[string]int, len(*m)+start_at)
+       i2e := make([]string, len(*m)+start_at)
+       i := start_at
        for e := range *m {
-               index[e] = i
+               e2i[e] = i
+               i2e[i] = e
                i++
        }
-       return index
+       return e2i, i2e
 }
-func IndexCommodities(m *map[string]Commodity) map[string]int {
-       index := make(map[string]int, len(*m))
-       i := 0
+func IndexCommodities(m *map[string]Commodity, start_at int) (map[string]int, []string) {
+       e2i := make(map[string]int, len(*m)+start_at)
+       i2e := make([]string, len(*m)+start_at)
+       i := start_at
        for e := range *m {
-               index[e] = i
+               e2i[e] = i
+               i2e[i] = e
                i++
        }
-       return index
+       return e2i, i2e
 }
 
 func main() {
        flag.Parse()
+       if *cpuprofile != "" {
+               f, err := os.Create(*cpuprofile)
+               if err != nil {
+                       panic(err)
+               }
+               pprof.StartCPUProfile(f)
+               defer pprof.StopCPUProfile()
+       }
        data := ReadData()
-       data.pi = IndexPlanets(&data.Planets)
-       data.ci = IndexCommodities(&data.Commodities)
+       if *drone_price > 0 {
+               temp := data.Commodities["Fighter Drones"]
+               temp.BasePrice = *drone_price
+               data.Commodities["Fighter Drones"] = temp
+       }
+       if *battery_price > 0 {
+               temp := data.Commodities["Shield Batterys"]
+               temp.BasePrice = *battery_price
+               data.Commodities["Shield Batterys"] = temp
+       }
+       data.p2i, data.i2p = IndexPlanets(&data.Planets, 0)
+       data.c2i, data.i2c = IndexCommodities(&data.Commodities, 1)
        dims := DimensionSizes(data)
-       table := NewStateTable(dims)
-       table[0] = State{1, 1}
-       best_trades := FindBestTrades(data)
-
-       for from := range data.Planets {
-               for to := range data.Planets {
-                       best_trade := "(nothing)"
-                       if best_trades[data.pi[from]][data.pi[to]] != "" {
-                               best_trade = best_trades[data.pi[from]][data.pi[to]]
-                       }
-                       fmt.Printf("%s to %s: %s\n", from, to, best_trade)
+       table := InitializeStateTable(data, dims)
+       FillStateTable1(data, dims, table)
+       best := FindBestState(data, dims, table)
+       if best == -1 {
+               print("Cannot acheive success criteria\n")
+       } else {
+               description := DescribePath(data, dims, table, best)
+               for i := len(description) - 1; i >= 0; i-- {
+                       fmt.Println(description[i])
                }
        }
 }