W. H. Freeman1979
A K PetersJuly 2009
translated byRyuhei Uehara
Complexity of Games & Puzzles
0 players(simulation)
1 player(puzzle)
2 players(game)
team,imperfect info
NP
PSPACE EXPTIME
P
Undecidable
NEXPTIMEPSPACE
PSPACE
Rengo Kriegspiel?
bridge?
Constraint Logic[Hearn & Demaine 2009]
PSPACE EXPTIME
P
Undecidable
NEXPTIME
PSPACE
NPPSPACE
0 players(simulation)
1 player(puzzle)
2 players(game)
team,imperfect info
Hamiltonian 𝒔𝒔, 𝒕𝒕 -Path
𝑣𝑣0 𝑣𝑣2 𝑣𝑣4
𝑣𝑣1
𝑣𝑣3
𝑠𝑠
𝑡𝑡𝑣𝑣0 𝑣𝑣2 𝑣𝑣4
𝑣𝑣1
𝑣𝑣3
𝑠𝑠
𝑡𝑡
input goal
100% Speedrun is NP-hard: MarioThe Lost Levels
Speedrun is NP-hard: Zelda
Speedrun is NP-hard: Metroidvania
Speedrun is NP-hard: RPG
Playing is NP-hard: Katamari
Edge-Matching Puzzles[1890s—]
photo by Matěj Baťha
[Christopher Monckton, 2007]US$2,000,000 prize (expired 2010)
NP-hardness of 𝟏𝟏 × 𝒏𝒏 Edge Matching
Reduction from Hamiltonian pathwith specified start 𝑠𝑠 & end vertex 𝑡𝑡
vertextile
edgetile
𝑣𝑣0 𝑣𝑣2 𝑣𝑣4
𝑣𝑣1
𝑣𝑣3
𝑠𝑠
𝑡𝑡
𝑠𝑠
𝑡𝑡
Bosboom, Demaine, Demaine, Hesterberg, Manurangsi, Yodpinyanee 2017
NP-hardness of 𝟏𝟏 × 𝒏𝒏 Edge Matching
or
𝐼𝐼𝑖𝑖 𝑂𝑂𝑖𝑖𝑈𝑈𝑖𝑖
𝑈𝑈𝑖𝑖𝐼𝐼𝑛𝑛𝑈𝑈𝑛𝑛
𝑈𝑈𝑛𝑛
𝑣𝑣𝑖𝑖 𝑡𝑡 = 𝑣𝑣𝑛𝑛𝑠𝑠 = 𝑣𝑣1
𝑣𝑣𝑖𝑖 ,𝑣𝑣𝑗𝑗 𝑣𝑣𝑖𝑖 ,𝑣𝑣𝑗𝑗
𝑂𝑂𝑖𝑖 𝐼𝐼𝑗𝑗𝑂𝑂𝑖𝑖
𝐼𝐼𝑗𝑗
NP-hardness
vertextile
edgetile
𝑣𝑣0 𝑣𝑣2 𝑣𝑣4
𝑣𝑣1
𝑣𝑣3
𝑠𝑠
𝑡𝑡
𝑠𝑠
𝑡𝑡
Bosboom, Demaine, Demaine, Hesterberg, Manurangsi, Yodpinyanee 2017