TIS-100 Bench: Sequence Indexer

62711 Medium Memory & interpreters Sequence algorithms Built-in puzzle · TIS-100 Bench report →

Store a zero-terminated sequence, then answer index lookups. Values must remain available for later requests.

In TIS-100 Bench, 16 LLMs each had one attempt at this TIS-100 puzzle, with 30 minutes to find a working program and keep improving it, without seeing the community leaderboard. 15 of 16 models solved it. No model found a new Pareto-frontier point beyond the community leaderboard.

15 / 16models solved it
989best LLM cycles (291 community)
0new frontier points

Records

ScoreCommunity bestBest LLMModel
Cycles291989Sonnet 5.5 · +240%
Nodes44GPT-6 Astra Ties record
Instructions1721Gemini 4 Argon · +24%

Community records from the community leaderboard when we froze it. A record counts only after fresh-game replay and 100,000 passing random tests.

Pareto frontier

Pareto explorer

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Select a point with the mouse or keyboard to inspect its scores and program.

Search over time

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Every model

ModelSolvedBest cyclesBest nodesBest instructionsNew frontier points
01Sonnet 5.5Yes989629—
02GPT-6.1 SolYes998425—
03Gemini 3.8 FlashYes1,025527—
04Fable 5.1Yes1,059632—
05Opus 5.5Yes1,068521—
06Haiku 5.5Yes1,080627—
07Gemini 4 ArgonYes1,092521—
08GPT-6 AstraYes1,123423—
09GLM-5.3Yes1,199638—
10Grok 4.7Yes1,424741—
11DeepSeek V4.1 FlashYes1,870535—
12Kimi K3.1 ProYes1,938526—
13Muse Spark 1.3Yes1,977522—
14GPT-6 LunaYes2,275625—
15Muse Wonder 1.0Yes2,770534—
16MiMo-V2.6-ProNo————

Best scores can come from different programs. New frontier points are not matched or beaten on all three scores by any community program.

Best model programs

These programs are in TIS-100 save format and released under the MIT License. All of this puzzle’s model programs are on GitHub and Hugging Face.

Sonnet 5.5 Fewest cycles

989 cycles · 6 nodes · 33 instructions62711.989-6-33.txt on GitHub

Sonnet 5.5 program running on 62711 in TIS-100
Node 0
L: MOV ACC, RIGHT
MOV UP, ACC
JNZ L
R: MOV RIGHT, ACC
MOV ACC, DOWN
JNZ R
Node 1
MOV UP, ACC
MOV ACC, DOWN
MOV ACC, DOWN
Node 2
MOV UP, RIGHT
Node 3
L: MOV ACC, DOWN
MOV LEFT, ACC
JNZ L
Q: MOV RIGHT, ACC
JGZ B
JEZ G
F: MOV DOWN, UP
ADD 1
JNZ F
JMP G
B: MOV UP, DOWN
SUB 1
JNZ B
G: MOV 0, RIGHT
JMP Q
Node 4
SUB UP
MOV ACC, LEFT
MOV UP, ACC
MOV LEFT, DOWN
Node 7
MOV UP, NIL
MOV LEFT, ACC
MOV ACC, DOWN
MOV ACC, LEFT

GPT-6.1 Sol Fewest nodes

3,051 cycles · 4 nodes · 36 instructions62711.3051-4-36.txt on GitHub

GPT-6.1 Sol program running on 62711 in TIS-100
Node 0
L: MOV UP ACC
JEZ L
MOV ACC RIGHT
Node 1
MOV 19 ACC
D: SUB 1
JNZ D
Q: MOV 9 ACC
SUB UP
JEZ T
L: MOV LEFT DOWN
SUB 1
JGZ L
T: MOV 0 DOWN
MOV LEFT DOWN
R: MOV DOWN ACC
JEZ Q
MOV ACC LEFT
JMP R
Node 4
F: MOV UP ACC
MOV ACC DOWN
JNZ F
MOV UP DOWN
R: MOV DOWN ACC
MOV ACC UP
JNZ R
Node 7
MOV 0 LEFT
F: MOV UP ACC
JEZ T
MOV ACC LEFT
JMP F
T: MOV UP ACC
MOV ACC DOWN
MOV ACC LEFT
R: MOV LEFT ACC
MOV ACC UP
JNZ R

Gemini 4 Argon Fewest instructions

2,130 cycles · 6 nodes · 21 instructions62711.2130-6-21.txt on GitHub

Gemini 4 Argon program running on 62711 in TIS-100
Node 0
MOV UP, DOWN
Node 1
MOV UP, DOWN
Node 2
MOV UP, RIGHT
Node 3
I: MOV ACC, UP
MOV LEFT, ACC
JNZ I
L: MOV ACC, DOWN
MOV UP, ACC
JNZ L
MOV ACC, UP
MOV RIGHT, ACC
C: SUB 1
JLZ F
MOV DOWN, UP
JMP C
F: MOV DOWN, ACC
MOV ACC, RIGHT
JMP L
Node 4
MOV UP, LEFT
MOV LEFT, DOWN
Node 7
MOV UP, DOWN