-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathDay12RainRisk.kt
891 lines (867 loc) · 12.6 KB
/
Day12RainRisk.kt
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
package aoc
import org.assertj.core.api.Assertions.assertThat
import org.junit.Test
class Day12RainRisk {
private data class Ship(
val pos: Point,
val direction: Int,
) {
fun move(where: Point): Ship = copy(pos = pos + where)
fun rotate(deg: Int): Ship = copy(direction = direction + deg)
fun moveForward(num: Int): Ship {
val angle = direction.rem(360).let { if (it < 0) 360 + it else it }
return when (angle) {
90 -> move(Point(x = 0, y = num))
270 -> move(Point(x = 0, y = -num))
0 -> move(Point(x = num, y = 0))
180 -> move(Point(x = -num, y = 0))
else -> error("Unknown direction: $direction")
}
}
}
@Test
fun silverTest() {
val positions = takeEvasiveActions(testInput)
printMap(positions
.map { ship -> ship.pos to '*' }
.toMap(), invertedY = false)
assertThat(positions.last().pos.manhattan()).isEqualTo(25)
}
@Test
fun silver() {
val positions = takeEvasiveActions(taskInput)
assertThat(positions.last().pos.manhattan()).isEqualTo(2879)
}
private fun takeEvasiveActions(input: String): List<Ship> {
val instructions = input.lines()
.filter { it.isNotBlank() }
.map { it.first() to it.substring(1).toInt() }
val positions = instructions.scan(Ship(pos = Point(0, 0), direction = 0)) { ship, (what, num) ->
ship.takeAction(what, num)
}
return positions
}
private fun Ship.takeAction(what: Char, num: Int): Ship {
return when (what) {
'N' -> move(Point(x = 0, y = -num))
'S' -> move(Point(x = 0, y = num))
'E' -> move(Point(x = num, y = 0))
'W' -> move(Point(x = -num, y = 0))
'L' -> rotate(-num)
'R' -> rotate(num)
'F' -> moveForward(num)
else -> error("wtf: $what")
}
}
data class WaypointShip(
val pos: Point,
val waypoint: Point,
) {
fun moveWaypoint(where: Point): WaypointShip = copy(waypoint = waypoint + where)
fun rotateWaypoint(deg: Int): WaypointShip {
return when (deg) {
90, -270 -> copy(waypoint = waypoint.rotateCCW())
180, -180 -> copy(waypoint = waypoint.rotateCCW().rotateCCW())
270, -90 -> copy(waypoint = waypoint.rotateCW())
else -> error("unsupported angle: $deg")
}
}
fun moveForward(num: Int): WaypointShip {
return copy(pos = pos + waypoint * num)
}
}
@Test
fun goldTest() {
val positions = takeEvasiveActionsWithWaypoint(testInput)
printMap(positions
.map { ship -> ship.pos to '*' }
.toMap(), invertedY = false)
assertThat(positions.last().pos.manhattan()).isEqualTo(286)
}
@Test
fun gold() {
val positions = takeEvasiveActionsWithWaypoint(taskInput)
assertThat(positions.last().pos.manhattan()).isEqualTo(178986)
}
private fun takeEvasiveActionsWithWaypoint(input: String): List<WaypointShip> {
val instructions = input.lines()
.filter { it.isNotBlank() }
.map { it.first() to it.substring(1).toInt() }
val initial = WaypointShip(
pos = Point(0, 0),
waypoint = Point(10, -1)
)
return instructions.scan(initial) { ship, (what, num) ->
ship.takeAction(what, num)
}
}
private fun WaypointShip.takeAction(what: Char, num: Int): WaypointShip {
return when (what) {
'N' -> moveWaypoint(Point(x = 0, y = -num))
'S' -> moveWaypoint(Point(x = 0, y = num))
'E' -> moveWaypoint(Point(x = num, y = 0))
'W' -> moveWaypoint(Point(x = -num, y = 0))
'L' -> rotateWaypoint(-num)
'R' -> rotateWaypoint(num)
'F' -> moveForward(num)
else -> error("wtf: $what")
}
}
private val testInput = """
F10
N3
F7
R90
F11
""".trimIndent()
private val taskInput = """
F75
L90
N5
W2
N5
L90
S1
R90
S4
E2
W1
F100
L180
W3
N1
R180
W1
S4
R270
S4
F23
E2
F17
N5
R90
F83
E2
F34
E3
S4
F19
W4
L90
W2
L90
E2
F79
L90
F80
N1
R90
F35
L90
N5
E3
S5
R90
F71
N1
F19
F49
R90
E4
L90
W1
R90
S2
E1
L180
F79
W4
L180
F74
W5
R90
F30
R90
W2
R90
F35
R90
F12
W2
F7
R90
E5
F68
E3
F21
N4
F22
W4
S2
F89
L90
N5
R90
F8
R90
W2
S3
R180
N2
R90
F49
N4
E5
F31
S3
E4
F61
E1
L90
N1
W5
F15
F13
E4
N2
R180
S2
L90
F92
S4
R180
L90
S1
L90
F98
N4
E3
F69
S3
R180
F59
S5
R90
F32
E5
S4
W4
F9
R180
F44
L90
W1
L180
F74
W1
F55
R270
S3
F62
W3
F61
N2
L90
F43
S3
F86
W1
S3
E3
F34
L90
F77
N1
F27
N5
W5
N3
F80
E2
L180
F59
W1
L90
N4
R90
W5
L180
W5
L90
F17
E5
L180
W4
R180
W4
F70
S5
R90
W4
W4
N3
W1
N2
E5
F53
N5
R90
R90
E2
N5
R270
S5
R90
N5
E1
R90
F76
R90
W3
S2
R90
S5
E1
L90
E2
F58
R90
F15
N2
L90
N5
F65
E5
N2
R90
W1
F40
S4
R90
F23
W4
R90
W4
F17
S2
R90
E4
F58
R90
L90
F64
N4
F63
E5
N1
F38
N3
F19
E5
S4
F14
R90
S3
E2
S4
E1
F12
W3
L90
F33
S4
W3
F29
R90
N3
F44
E5
N1
F49
W5
F52
N5
L90
S4
F31
R90
N3
L270
L270
E4
N4
W1
L90
S5
W4
R180
N3
L180
F2
S1
L180
N3
L90
N1
W4
R180
W5
R270
N4
L180
F51
R180
S5
F35
E3
R180
F1
S3
E2
F47
E4
S5
E1
L90
F16
S4
F17
N1
W2
L90
F99
E1
R180
N1
F78
L90
F18
S2
W3
N2
F56
R270
W1
R90
F53
L180
F6
W5
R90
W4
F27
R90
F73
E5
R90
W4
S4
W3
S2
E5
N5
R270
F43
W1
F77
E4
F85
W2
R90
N1
E1
F39
R90
W2
N4
E2
W4
F81
W4
F3
W4
R180
W2
N5
R90
N5
E2
S5
S3
E1
N4
W1
S3
F48
S2
F23
E2
R180
F89
L180
N3
E1
N5
W2
L90
E1
F80
R90
S1
E3
N5
L90
F11
W5
F70
N3
W1
L90
N5
F99
N5
F24
R180
E4
F57
S1
F9
S5
R90
W4
F16
E1
F18
F17
L180
S1
L90
S1
E2
N1
E4
F84
N1
F6
E1
L180
W3
L180
N3
F60
F43
S3
F48
W2
S1
R180
N1
S2
F78
L180
W4
F51
W5
N2
E2
N1
W4
F65
N3
L90
W3
N2
W2
F46
N4
W4
N2
W2
F74
R180
E4
R90
N1
F33
S4
L180
S1
F15
R180
S5
L180
F21
N4
F87
W4
L90
S4
F40
S5
W3
L180
F78
W2
F40
N3
E3
S4
W1
S4
E1
S4
W5
S2
F82
E5
R180
F7
W3
R90
N2
R90
W5
N5
W5
S3
E2
L90
E1
F77
E4
F70
W5
S2
W2
F7
W4
F8
R180
W5
L90
F49
W2
L90
S5
W1
S3
F74
W3
F76
W3
N1
E4
S2
F65
E1
W1
F85
E5
F67
R90
W1
F8
R180
N2
F94
W4
R90
S4
F81
N5
R90
E4
F9
N3
F49
R180
N3
F94
N4
R90
S2
F34
W2
E4
W5
F84
S4
W1
R180
W5
F13
W3
L90
N1
E1
R90
S2
R180
F81
L90
F36
W3
S4
W1
F3
R90
W3
R90
E5
R90
F46
L90
F63
N1
L90
W4
N1
S2
N3
L90
F64
W5
N4
F45
W4
S4
R90
W3
N5
R90
L180
E4
R270
S1
L180
E1
F22
E4
F11
W3
F12
W3
R90
S5
E3
F4
R90
S3
F3
L180
S2
F16
E5
R90
F75
W4
N1
S4
F81
L90
F69
N5
L90
W5
F63
N3
W2
L90
F39
E5
F81
W3
F1
L90
F31
W4
S4
F32
W3
N4
L180
N5
W2
F20
L90
F42
S3
E5
S4
L90
S2
L90
S3
W5
F54
R90
F85
S4
F22
W3
F21
R90
F66
S1
F22
S4
W5
N5
E3
F52
L180
W3
S1
W5
R180
F43
E5
F16
W4
S5
W5
N4
F97
E5
F4
E2
R180
F99
S5
F44
R90
W5
N2
L90
F46
E4
L180
E4
R90
F45
R90
S4
F30
R90
F23
N5
W2
F45
S3
F70
L90
W2
F90
W5
F81
E2
F15
L90
F90
N2
F78
S4
F3
F37
""".trimIndent()
}