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1 /* Planeteer: Give trade route advice for Planets: The Exploration of Space
2 * Copyright (C) 2011 Scott Worley <sworley@chkno.net>
3 *
4 * This program is free software: you can redistribute it and/or modify
5 * it under the terms of the GNU Affero General Public License as
6 * published by the Free Software Foundation, either version 3 of the
7 * License, or (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU Affero General Public License for more details.
13 *
14 * You should have received a copy of the GNU Affero General Public License
15 * along with this program. If not, see <http://www.gnu.org/licenses/>.
16 */
17
18 package main
19
20 import "flag"
21 import "fmt"
22 import "json"
23 import "os"
24 import "strings"
25
26 var funds = flag.Int("funds", 0,
27 "Starting funds")
28
29 var start = flag.String("start", "",
30 "The planet to start at")
31
32 var flight_plan_string = flag.String("flight_plan", "",
33 "Your hidey-holes for the day, comma-separated.")
34
35 var end_string = flag.String("end", "",
36 "A comma-separated list of acceptable ending planets.")
37
38 var planet_data_file = flag.String("planet_data_file", "planet-data",
39 "The file to read planet data from")
40
41 var fuel = flag.Int("fuel", 16, "Reactor units")
42
43 var hold = flag.Int("hold", 300, "Size of your cargo hold")
44
45 var start_edens = flag.Int("start_edens", 0,
46 "How many Eden Warp Units are you starting with?")
47
48 var end_edens = flag.Int("end_edens", 0,
49 "How many Eden Warp Units would you like to keep (not use)?")
50
51 var cloak = flag.Bool("cloak", false,
52 "Make sure to end with a Device of Cloaking")
53
54 var drones = flag.Int("drones", 0, "Buy this many Fighter Drones")
55
56 var batteries = flag.Int("batteries", 0, "Buy this many Shield Batterys")
57
58 var visit_string = flag.String("visit", "",
59 "A comma-separated list of planets to make sure to visit")
60
61 func visit() []string {
62 if *visit_string == "" {
63 return nil
64 }
65 return strings.Split(*visit_string, ",")
66 }
67
68 func flight_plan() []string {
69 if *flight_plan_string == "" {
70 return nil
71 }
72 return strings.Split(*flight_plan_string, ",")
73 }
74
75 func end() map[string]bool {
76 if *end_string == "" {
77 return nil
78 }
79 m := make(map[string]bool)
80 for _, p := range strings.Split(*flight_plan_string, ",") {
81 m[p] = true
82 }
83 return m
84 }
85
86 type Commodity struct {
87 BasePrice int
88 CanSell bool
89 Limit int
90 }
91 type Planet struct {
92 BeaconOn bool
93 /* Use relative prices rather than absolute prices because you
94 can get relative prices without traveling to each planet. */
95 RelativePrices map[string]int
96 }
97 type planet_data struct {
98 Commodities map[string]Commodity
99 Planets map[string]Planet
100 p2i, c2i map[string]int // Generated; not read from file
101 i2p, i2c []string // Generated; not read from file
102 }
103
104 func ReadData() (data planet_data) {
105 f, err := os.Open(*planet_data_file)
106 if err != nil {
107 panic(err)
108 }
109 defer f.Close()
110 err = json.NewDecoder(f).Decode(&data)
111 if err != nil {
112 panic(err)
113 }
114 return
115 }
116
117 /* This program operates by filling in a state table representing the best
118 * possible trips you could make; the ones that makes you the most money.
119 * This is feasible because we don't look at all the possible trips.
120 * We define a list of things that are germane to this game and then only
121 * consider the best outcome in each possible game state.
122 *
123 * Each cell in the table represents a state in the game. In each cell,
124 * we track two things: 1. the most money you could possibly have while in
125 * that state and 2. one possible way to get into that state with that
126 * amount of money.
127 *
128 * A basic analysis can be done with a two-dimensional table: location and
129 * fuel. planeteer-1.0 used this two-dimensional table. This version
130 * adds features mostly by adding dimensions to this table.
131 *
132 * Note that the sizes of each dimension are data driven. Many dimensions
133 * collapse to one possible value (ie, disappear) if the corresponding
134 * feature is not enabled.
135 *
136 * The order of the dimensions in the list of constants below determines
137 * their layout in RAM. The cargo-based 'dimensions' are not completely
138 * independent -- some combinations are illegal and not used. They are
139 * handled as three dimensions rather than one for simplicity. Placing
140 * these dimensions first causes the unused cells in the table to be
141 * grouped together in large blocks. This keeps them from polluting
142 * cache lines, and if they are large enough, prevent the memory manager
143 * from allocating pages for these areas at all.
144 *
145 * If the table gets too big to fit in RAM:
146 * * Combine the Edens, Cloaks, and UnusedCargo dimensions. Of the
147 * 24 combinations, only 15 are legal: a 38% savings.
148 * * Reduce the size of the Fuel dimension to 3. We only ever look
149 * backwards 2 units, so just rotate the logical values through
150 * the same 3 physical addresses. This is good for an 82% savings.
151 * * Reduce the size of the Edens dimension from 3 to 2, for the
152 * same reasons as Fuel above. 33% savings.
153 * * Buy more ram. (Just sayin'. It's cheaper than you think.)
154 *
155 */
156
157 // The official list of dimensions:
158 const (
159 // Name Num Size Description
160 Edens = iota // 1 3 # of Eden warp units (0 - 2 typically)
161 Cloaks // 2 2 # of Devices of Cloaking (0 or 1)
162 UnusedCargo // 3 4 # of unused cargo spaces (0 - 3 typically)
163 Fuel // 4 17 Reactor power left (0 - 16)
164 Location // 5 26 Location (which planet)
165 Hold // 6 15 Cargo bay contents (a *Commodity or nil)
166 NeedFighters // 7 2 Errand: Buy fighter drones (needed or not)
167 NeedShields // 8 2 Errand: Buy shield batteries (needed or not)
168 Visit // 9 2**N Visit: Stop by these N planets in the route
169
170 NumDimensions
171 )
172
173 func bint(b bool) int {
174 if b {
175 return 1
176 }
177 return 0
178 }
179
180 func DimensionSizes(data planet_data) []int {
181 eden_capacity := data.Commodities["Eden Warp Units"].Limit
182 if *start_edens > eden_capacity {
183 eden_capacity = *start_edens
184 }
185 cloak_capacity := bint(*cloak)
186 dims := make([]int, NumDimensions)
187 dims[Edens] = eden_capacity + 1
188 dims[Cloaks] = cloak_capacity + 1
189 dims[UnusedCargo] = eden_capacity + cloak_capacity + 1
190 dims[Fuel] = *fuel + 1
191 dims[Location] = len(data.Planets)
192 dims[Hold] = len(data.Commodities) + 1
193 dims[NeedFighters] = bint(*drones > 0) + 1
194 dims[NeedShields] = bint(*batteries > 0) + 1
195 dims[Visit] = 1 << uint(len(visit()))
196
197 // Remind myself to add a line above when adding new dimensions
198 for i, dim := range dims {
199 if dim < 1 {
200 panic(i)
201 }
202 }
203 return dims
204 }
205
206 func StateTableSize(dims []int) int {
207 product := 1
208 for _, size := range dims {
209 product *= size
210 }
211 return product
212 }
213
214 type State struct {
215 value, from int
216 }
217
218 func EncodeIndex(dims, addr []int) int {
219 index := addr[0]
220 if addr[0] > dims[0] {
221 panic(0)
222 }
223 for i := 1; i < NumDimensions; i++ {
224 if addr[i] > dims[i] {
225 panic(i)
226 }
227 index = index*dims[i] + addr[i]
228 }
229 return index
230 }
231
232 func DecodeIndex(dims []int, index int) []int {
233 addr := make([]int, NumDimensions)
234 for i := NumDimensions - 1; i > 0; i-- {
235 addr[i] = index % dims[i]
236 index /= dims[i]
237 }
238 addr[0] = index
239 return addr
240 }
241
242 func InitializeStateTable(data planet_data, dims []int) []State {
243 table := make([]State, StateTableSize(dims))
244
245 addr := make([]int, NumDimensions)
246 addr[Fuel] = *fuel
247 addr[Edens] = *start_edens
248 addr[Location] = data.p2i[*start]
249 table[EncodeIndex(dims, addr)].value = *funds
250
251 return table
252 }
253
254 /* These four fill procedures fill in the cell at address addr by
255 * looking at all the possible ways to reach this cell and selecting
256 * the best one.
257 *
258 * The other obvious implementation choice is to do this the other way
259 * around -- for each cell, conditionally overwrite all the other cells
260 * that are reachable *from* the considered cell. We choose gathering
261 * reads over scattering writes to avoid having to take a bunch of locks.
262 */
263
264 func UpdateCell(table []State, here, there, value_difference int) {
265 possible_value := table[there].value + value_difference
266 if table[there].value > 0 && possible_value > table[here].value {
267 table[here].value = possible_value
268 table[here].from = there
269 }
270 }
271
272 func FillCellByArriving(data planet_data, dims []int, table []State, addr []int) {
273 my_index := EncodeIndex(dims, addr)
274 other := make([]int, NumDimensions)
275 copy(other, addr)
276
277 /* Travel here via a 2-fuel unit jump */
278 if addr[Fuel]+2 < dims[Fuel] {
279 other[Fuel] = addr[Fuel] + 2
280 for other[Location] = 0; other[Location] < dims[Location]; other[Location]++ {
281 if data.Planets[data.i2p[addr[Location]]].BeaconOn {
282 UpdateCell(table, my_index, EncodeIndex(dims, other), 0)
283 }
284 }
285 other[Location] = addr[Location]
286 other[Fuel] = addr[Fuel]
287 }
288
289 /* Travel here via a hidey hole */
290 if addr[Fuel]+1 < dims[Fuel] {
291 hole_index := (dims[Fuel] - 1) - (addr[Fuel] + 1)
292 if hole_index < len(flight_plan()) && addr[Location] == data.p2i[flight_plan()[hole_index]] {
293 other[Fuel] = addr[Fuel] + 1
294 for other[Location] = 0; other[Location] < dims[Location]; other[Location]++ {
295 UpdateCell(table, my_index, EncodeIndex(dims, other), 0)
296 }
297 other[Location] = addr[Location]
298 other[Fuel] = addr[Fuel]
299 }
300 }
301
302 /* Travel here via Eden Warp Unit */
303 if addr[Edens]+1 < dims[Edens] {
304 _, available := data.Planets[data.i2p[addr[Location]]].RelativePrices["Eden Warp Units"]
305 if !available {
306 other[Edens] = addr[Edens] + 1
307 for other[Location] = 0; other[Location] < dims[Location]; other[Location]++ {
308 UpdateCell(table, my_index, EncodeIndex(dims, other), 0)
309 }
310 other[Location] = addr[Location]
311 other[Edens] = addr[Edens]
312 }
313 }
314 }
315
316 func FillCellBySelling(data planet_data, dims []int, table []State, addr []int) {
317 if addr[Hold] > 0 {
318 // Can't sell and still have cargo
319 return
320 }
321 if addr[UnusedCargo] > 0 {
322 // Can't sell everything and still have 'unused' holds
323 return
324 }
325 my_index := EncodeIndex(dims, addr)
326 other := make([]int, NumDimensions)
327 copy(other, addr)
328 planet := data.i2p[addr[Location]]
329 for other[Hold] = 0; other[Hold] < dims[Hold]; other[Hold]++ {
330 commodity := data.i2c[other[Hold]]
331 if !data.Commodities[commodity].CanSell {
332 // TODO: Dump cargo
333 continue
334 }
335 relative_price, available := data.Planets[planet].RelativePrices[commodity]
336 if !available {
337 continue
338 }
339 base_price := data.Commodities[commodity].BasePrice
340 absolute_price := float64(base_price) * float64(relative_price) / 100.0
341 sell_price := int(absolute_price * 0.9)
342
343 for other[UnusedCargo] = 0; other[UnusedCargo] < dims[UnusedCargo]; other[UnusedCargo]++ {
344
345 quantity := *hold - (other[UnusedCargo] + other[Cloaks] + other[Edens])
346 sale_value := quantity * sell_price
347 UpdateCell(table, my_index, EncodeIndex(dims, other), sale_value)
348 }
349 }
350 other[UnusedCargo] = addr[UnusedCargo]
351 }
352
353 func FillCellByBuying(data planet_data, dims []int, table []State, addr []int) {
354 if addr[Hold] == 0 {
355 // Can't buy and then have nothing
356 return
357 }
358 my_index := EncodeIndex(dims, addr)
359 other := make([]int, NumDimensions)
360 copy(other, addr)
361 planet := data.i2p[addr[Location]]
362 commodity := data.i2c[addr[Hold]]
363 if !data.Commodities[commodity].CanSell {
364 return
365 }
366 relative_price, available := data.Planets[planet].RelativePrices[commodity]
367 if !available {
368 return
369 }
370 base_price := data.Commodities[commodity].BasePrice
371 absolute_price := int(float64(base_price) * float64(relative_price) / 100.0)
372 quantity := *hold - (addr[UnusedCargo] + addr[Cloaks] + addr[Edens])
373 total_price := quantity * absolute_price
374 other[Hold] = 0
375 other[UnusedCargo] = 0
376 UpdateCell(table, my_index, EncodeIndex(dims, other), -total_price)
377 other[UnusedCargo] = addr[UnusedCargo]
378 other[Hold] = addr[Hold]
379 }
380
381 func FillCellByMisc(data planet_data, dims []int, table []State, addr []int) {
382 my_index := EncodeIndex(dims, addr)
383 other := make([]int, NumDimensions)
384 copy(other, addr)
385 /* Buy Eden warp units */
386 /* Buy a Device of Cloaking */
387 if addr[Cloaks] == 1 && addr[UnusedCargo] < dims[UnusedCargo]-1 {
388 relative_price, available := data.Planets[data.i2p[addr[Location]]].RelativePrices["Device Of Cloakings"]
389 if available {
390 absolute_price := int(float64(data.Commodities["Device Of Cloakings"].BasePrice) * float64(relative_price) / 100.0)
391 other[Cloaks] = 0
392 if other[Hold] != 0 {
393 other[UnusedCargo] = addr[UnusedCargo] + 1
394 }
395 UpdateCell(table, my_index, EncodeIndex(dims, other), -absolute_price)
396 other[UnusedCargo] = addr[UnusedCargo]
397 other[Cloaks] = addr[Cloaks]
398 }
399 }
400 /* Silly: Dump a Device of Cloaking */
401 /* Buy Fighter Drones */
402 /* Buy Shield Batteries */
403 /* Visit this planet */
404 }
405
406 func FillStateTable2Iteration(data planet_data, dims []int, table []State,
407 addr []int, f func(planet_data, []int, []State, []int)) {
408 /* TODO: Justify the safety of the combination of this dimension
409 * iteration and the various phases f. */
410 for addr[Hold] = 0; addr[Hold] < dims[Hold]; addr[Hold]++ {
411 for addr[Cloaks] = 0; addr[Cloaks] < dims[Cloaks]; addr[Cloaks]++ {
412 for addr[UnusedCargo] = 0; addr[UnusedCargo] < dims[UnusedCargo]; addr[UnusedCargo]++ {
413 for addr[NeedFighters] = 0; addr[NeedFighters] < dims[NeedFighters]; addr[NeedFighters]++ {
414 for addr[NeedShields] = 0; addr[NeedShields] < dims[NeedShields]; addr[NeedShields]++ {
415 for addr[Visit] = 0; addr[Visit] < dims[Visit]; addr[Visit]++ {
416 f(data, dims, table, addr)
417 }
418 }
419 }
420 }
421 }
422 }
423 }
424
425 func FillStateTable2(data planet_data, dims []int, table []State,
426 fuel_remaining, edens_remaining int, planet string, barrier chan<- bool) {
427 addr := make([]int, len(dims))
428 addr[Edens] = edens_remaining
429 addr[Fuel] = fuel_remaining
430 addr[Location] = data.p2i[planet]
431 FillStateTable2Iteration(data, dims, table, addr, FillCellByArriving)
432 FillStateTable2Iteration(data, dims, table, addr, FillCellBySelling)
433 FillStateTable2Iteration(data, dims, table, addr, FillCellByBuying)
434 FillStateTable2Iteration(data, dims, table, addr, FillCellByMisc)
435 barrier <- true
436 }
437
438 /* Filling the state table is a set of nested for loops NumDimensions deep.
439 * We split this into two procedures: 1 and 2. #1 is the outer, slowest-
440 * changing indexes. #1 fires off many calls to #2 that run in parallel.
441 * The order of the nesting of the dimensions, the order of iteration within
442 * each dimension, and where the 1 / 2 split is placed are carefully chosen
443 * to make this arrangement safe.
444 *
445 * Outermost two layers: Go from high-energy states (lots of fuel, edens) to
446 * low-energy state. These must be processed sequentially and in this order
447 * because you travel through high-energy states to get to the low-energy
448 * states.
449 *
450 * Third layer: Planet. This is a good layer to parallelize on. There's
451 * high enough cardinality that we don't have to mess with parallelizing
452 * multiple layers for good utilization (on 2011 machines). Each thread
453 * works on one planet's states and need not synchronize with peer threads.
454 */
455 func FillStateTable1(data planet_data, dims []int, table []State) {
456 barrier := make(chan bool, len(data.Planets))
457 eden_capacity := data.Commodities["Eden Warp Units"].Limit
458 work_units := (float64(*fuel) + 1) * (float64(eden_capacity) + 1)
459 work_done := 0.0
460 for fuel_remaining := *fuel; fuel_remaining >= 0; fuel_remaining-- {
461 for edens_remaining := eden_capacity; edens_remaining >= 0; edens_remaining-- {
462 for planet := range data.Planets {
463 go FillStateTable2(data, dims, table, fuel_remaining,
464 edens_remaining, planet, barrier)
465 }
466 for _ = range data.Planets {
467 <-barrier
468 }
469 work_done++
470 print(fmt.Sprintf("\r%3.0f%%", 100*work_done/work_units))
471 }
472 }
473 print("\n")
474 }
475
476 func FindBestState(data planet_data, dims []int, table []State) int {
477 addr := make([]int, NumDimensions)
478 addr[Edens] = *end_edens
479 addr[Cloaks] = dims[Cloaks] - 1
480 addr[NeedFighters] = dims[NeedFighters] - 1
481 addr[NeedShields] = dims[NeedShields] - 1
482 addr[Visit] = dims[Visit] - 1
483 // Fuel, Hold, UnusedCargo left at 0
484 max_index := -1
485 max_value := 0
486 for addr[Location] = 0; addr[Location] < dims[Location]; addr[Location]++ {
487 index := EncodeIndex(dims, addr)
488 if table[index].value > max_value {
489 max_value = table[index].value
490 max_index = index
491 }
492 }
493 return max_index
494 }
495
496 func Commas(n int) (s string) {
497 r := n % 1000
498 n /= 1000
499 for n > 0 {
500 s = fmt.Sprintf(",%03d", r) + s
501 r = n % 1000
502 n /= 1000
503 }
504 s = fmt.Sprint(r) + s
505 return
506 }
507
508 func DescribePath(data planet_data, dims []int, table []State, start int) (description []string) {
509 for index := start; index > 0 && table[index].from > 0; index = table[index].from {
510 line := fmt.Sprintf("%13v", Commas(table[index].value))
511 addr := DecodeIndex(dims, index)
512 prev := DecodeIndex(dims, table[index].from)
513 if addr[Location] != prev[Location] {
514 from := data.i2p[prev[Location]]
515 to := data.i2p[addr[Location]]
516 if addr[Fuel] != prev[Fuel] {
517 line += fmt.Sprintf(" Jump from %v to %v (%v reactor units)", from, to, prev[Fuel]-addr[Fuel])
518 } else if addr[Edens] != prev[Edens] {
519 line += fmt.Sprintf(" Eden warp from %v to %v", from, to)
520 } else {
521 panic("Traveling without fuel?")
522 }
523 }
524 if addr[Hold] != prev[Hold] {
525 if addr[Hold] == 0 {
526 quantity := *hold - (prev[UnusedCargo] + prev[Edens] + prev[Cloaks])
527 line += fmt.Sprintf(" Sell %v %v", quantity, data.i2c[prev[Hold]])
528 } else if prev[Hold] == 0 {
529 quantity := *hold - (addr[UnusedCargo] + addr[Edens] + addr[Cloaks])
530 line += fmt.Sprintf(" Buy %v %v", quantity, data.i2c[addr[Hold]])
531 } else {
532 panic("Switched cargo?")
533 }
534
535 }
536 if addr[Cloaks] == 1 && prev[Cloaks] == 0 {
537 // TODO: Dump cloaks, convert from cargo?
538 line += " Buy a Cloak"
539 }
540 description = append(description, line)
541 }
542 return
543 }
544
545 // (Example of a use case for generics in Go)
546 func IndexPlanets(m *map[string]Planet, start_at int) (map[string]int, []string) {
547 e2i := make(map[string]int, len(*m)+start_at)
548 i2e := make([]string, len(*m)+start_at)
549 i := start_at
550 for e := range *m {
551 e2i[e] = i
552 i2e[i] = e
553 i++
554 }
555 return e2i, i2e
556 }
557 func IndexCommodities(m *map[string]Commodity, start_at int) (map[string]int, []string) {
558 e2i := make(map[string]int, len(*m)+start_at)
559 i2e := make([]string, len(*m)+start_at)
560 i := start_at
561 for e := range *m {
562 e2i[e] = i
563 i2e[i] = e
564 i++
565 }
566 return e2i, i2e
567 }
568
569 func main() {
570 flag.Parse()
571 data := ReadData()
572 data.p2i, data.i2p = IndexPlanets(&data.Planets, 0)
573 data.c2i, data.i2c = IndexCommodities(&data.Commodities, 1)
574 dims := DimensionSizes(data)
575 table := InitializeStateTable(data, dims)
576 FillStateTable1(data, dims, table)
577 best := FindBestState(data, dims, table)
578 if best == -1 {
579 print("Cannot acheive success criteria\n")
580 } else {
581 description := DescribePath(data, dims, table, best)
582 for i := len(description) - 1; i >= 0; i-- {
583 fmt.Println(description[i])
584 }
585 }
586 }