Problem Statement
You are given
Definition
- Class:
- PyramidSequences
- Method:
- distinctPairs
- Parameters:
- int, int
- Returns:
- long
- Method signature:
- long distinctPairs(int N, int M)
- (be sure your method is public)
Constraints
- N will be between 2 and 1,000,000,000, inclusive.
- M will be between 2 and 1,000,000,000, inclusive.
Examples
3
4
Returns: 6
These are the first several terms of pyramid sequences of height 3 and 4: {1, 2, 3, 2, 1, 2, 3, 2, 1, 2, 3, 2, 1} {1, 2, 3, 4, 3, 2, 1, 2, 3, 4, 3, 2, 1} We can see the following pairs: (1, 1), (2, 2), (3, 3), (2, 4), (1, 3), (3, 1). No other pairs will appear later in the sequences.
3
5
Returns: 5
The sequences begin with: {1, 2, 3, 2, 1, 2, 3, 2, 1} {1, 2, 3, 4, 5, 4, 3, 2, 1}
43
76
Returns: 895
2
1000000000
Returns: 1000000000
100000
95555
Returns: 4777750000
1000000000
1000000000
Returns: 1000000000
1000000000
999999999
Returns: 499999999500000000
438483157
765337608
Returns: 167793825263334228
688253904
57365928
Returns: 19741161951291456
110532835
560034097
Returns: 9457273853694310
999624130
743084835
Returns: 371402765851534275
494388873
449911164
Returns: 111215536660039086
556899004
396135040
Returns: 61279780234524040
995823432
418011900
Returns: 208133022437420400
177532453
720048931
Returns: 19529896923849004
726839826
897052143
Returns: 326006611765523559
7629670
618515310
Returns: 2359533852623850
861795970
832466670
Returns: 358708210682659950
834829201
67355939
Returns: 1629523005048529
709350356
131572821
Returns: 16799620867655516
433425880
876727495
Returns: 39876163902521440
570228485
542319820
Returns: 154623104672036350
140716365
130579644
Returns: 9187346423337030
165181264
813247300
Returns: 37314782379782160
933240150
816127797
Returns: 380821613845724775
437485610
226499070
Returns: 49545041901691350
577058130
232349795
Returns: 67039669104291675
278862508
757286908
Returns: 58660812784995972
34842194
768489304
Returns: 13387926708446488
725082608
169706632
Returns: 61525663662728128
526099750
755810755
Returns: 110453291316679736
305488380
18281492
Returns: 2792391687531480
241459754
362348887
Returns: 43746336558596899
6253746
479431020
Returns: 1499119911800460
228110100
74451844
Returns: 8491608790012200
76875564
113992570
Returns: 4381621555279740
896081580
703221384
Returns: 315071864432253360
138962876
472092224
Returns: 32801646592138112
683380145
190583386
Returns: 65120450979635485
571057504
40578576
Returns: 11586350163217152
885609226
750115202
Returns: 332154471727026826
377552871
530779593
Returns: 75149009588469006
460705125
152740610
Returns: 35184190911313125
997721556
274778838
Returns: 137076384902615964
704113577
707166484
Returns: 248962761291876634
175737134
390362864
Returns: 5953001091182758
230923259
749055195
Returns: 791640074967035
851567625
965109975
Returns: 308196153250875066
427460970
213730485
Returns: 45680720218335225
471421650
432938250
Returns: 102048232081556250
184314696
645101436
Returns: 21402301445437332
155956070
62382428
Returns: 4864459153968980
552228807
321446619
Returns: 66567030987498147
706290900
141258180
Returns: 49884683542281000
167371182
781065516
Returns: 65363929316179956
408220246
816440492
Returns: 166643769244300516
482047535
96409507
Returns: 17427736877661087
557520568
487830497
Returns: 135987767887581148
73042544
730425440
Returns: 26676066169959680
132668850
66334425
Returns: 4400255940080625
65055480
628869640
Returns: 20455708143813600
893385276
372243865
Returns: 166278594036165870
670321072
335160536
Returns: 112332584891807296
682490988
909987984
Returns: 310529299134144096
967293708
322431236
Returns: 155942852922731544
710718800
177679700
Returns: 63140151584180000
305776700
580975730
Returns: 88824420749745500
635903772
272530188
Returns: 86651487266534568
958991352
599369595
Returns: 287395129128371220
73911756
381877406
Returns: 5080541301290156
568410521
81201503
Returns: 17308420653628396
818179440
545452960
Returns: 223139198679571200
521717104
586931742
Returns: 153106164340957584
74911698
674205282
Returns: 25252931237594418
373344138
871136322
Returns: 162616819608790218
689346240
258504840
Returns: 89099669737900800
779727928
334169112
Returns: 130280494650679968
622742865
415161910
Returns: 129269558636136075
140388369
233980615
Returns: 12318058797253978
268042423
536084846
Returns: 71846740527710929
286977500
631350500
Returns: 90591694056875000
63025270
882353780
Returns: 27805292610010300
331424148
552373580
Returns: 91534971564604920
989674140
913545360
Returns: 452056109254495200
956688586
956688586
Returns: 956688586
191942492
959712460
Returns: 92104800587925160
425329764
389885617
Returns: 82914978732802194
100000
20000000
Returns: 1000000000000
320189654
823344823
Returns: 5763413704
631
219
Returns: 51715
999999999
999999997
Returns: 374999998250000002
5
7
Returns: 12