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07 / independentset

Maximum Independent Set

Unweighted MIS on Hard Graphs
Binary QUBO graph-theory NP-hard benchmark-classic
Instances 50
Optimally solved 39 / 50
Variable range 17–4,000
Objective maximize

Overview

The Maximum Independent Set Problem is a fundamental graph optimization problem with applications in scheduling, resource allocation, and network design. Despite its simple formulation, it is NP-hard and challenging even for moderately-sized graphs.

Problem Description

Given a graph $G=(V,E)$, find an independent set $I \subseteq V$ of maximum cardinality.

Definition: A set $I \subseteq V$ is independent (or stable ) if no two vertices in $I$ are adjacent, i.e., there does not exist an edge $(u,v) \in E$ with $u, v \in I$.

Objective: Maximize $|I|$.

Performance

Runtime to reach best-known objective

Sorted instances vs total runtime. A point (x, y) means x instances were solved within y seconds. Solid line + filled circle = proven exact; dashed line + open diamond = heuristic. Lower-right is better.

Classical (50 · 2 exact, 48 heuristic) Quantum simulator (1 · heuristic) Quantum hardware (24 · heuristic)
Cactus plot: cumulative number of instances solved (horizontal) versus total runtime in seconds on a log scale (vertical), one line per method group; lower-right is better.00.010.1110100091827364550instances solved →runtime (s, log)Classical · exact · mammalia-kangaroo-interactions · 0 sClassical · exact · football · 0 sClassical · heuristic · johnson8-2-4 · 3.0e-4 sClassical · heuristic · ibm32 · 3.0e-4 sClassical · heuristic · karate · 3.0e-4 sClassical · heuristic · chesapeake · 3.0e-4 sClassical · heuristic · aves-sparrow-social · 3.0e-4 sClassical · heuristic · farm · 4.0e-4 sClassical · heuristic · insecta-ant-colony1-day38 · 4.0e-4 sClassical · heuristic · hamming6-2 · 4.0e-4 sClassical · heuristic · hamming6-4 · 4.0e-4 sClassical · heuristic · sloane_1dc_64 · 4.0e-4 sClassical · heuristic · johnson8-4-4 · 4.0e-4 sClassical · heuristic · es60fst03 · 4.0e-4 sClassical · heuristic · es60fst01 · 4.0e-4 sClassical · heuristic · C125-9 · 4.0e-4 sClassical · heuristic · c-fat200-1 · 4.0e-4 sClassical · heuristic · sloane_1dc_128 · 5.0e-4 sClassical · heuristic · sloane_1zc_128 · 5.0e-4 sClassical · heuristic · MANN-a9 · 6.0e-4 sClassical · heuristic · es60fst02 · 6.0e-4 sClassical · heuristic · johnson16-2-4 · 7.0e-4 sClassical · heuristic · insecta-ant-colony3-day09 · 8.0e-4 sClassical · heuristic · keller4 · 8.0e-4 sClassical · heuristic · brock200-3 · 9.0e-4 sClassical · heuristic · gen200_p0-9_44 · 9.0e-4 sClassical · heuristic · sloane_2dc_128 · 0 sClassical · heuristic · es60fst04 · 0 sClassical · heuristic · brock200-1 · 0 sClassical · heuristic · brock200-4 · 0 sClassical · heuristic · brock200-2 · 0 sClassical · heuristic · p_hat1500-3 · 0.19 sClassical · heuristic · hamming10-4 · 1.43 sClassical · heuristic · p_hat1500-1 · 2.49 sClassical · heuristic · C500-9 · 5.01 sClassical · heuristic · socfb-haverford76 · 5.01 sClassical · heuristic · socfb-trinity100 · 5.02 sClassical · heuristic · sorrell4 · 5.06 sClassical · heuristic · frb100-40 · 5.06 sClassical · heuristic · brock400-1 · 8.47 sClassical · heuristic · C4000-5 · 12.3 sClassical · heuristic · frb45-21-3 · 30 sClassical · heuristic · frb59-26-2 · 30 sClassical · heuristic · R_500_005_1 · 60 sClassical · heuristic · keller6 · 60.1 sClassical · heuristic · frb53-24-1 · 120 sClassical · heuristic · R_1000_005_1 · 120 sClassical · heuristic · frb50-23-3 · 120 sClassical · heuristic · sorrell7 · 120 sClassical · heuristic · brock800-1 · 120 sQuantum simulator · heuristic · es60fst02 · 61.3 sQuantum hardware · heuristic · sloane_1dc_128 · 2.18 sQuantum hardware · heuristic · sloane_1zc_128 · 2.39 sQuantum hardware · heuristic · es60fst04 · 2.46 sQuantum hardware · heuristic · es60fst02 · 2.56 sQuantum hardware · heuristic · C125-9 · 2.94 sQuantum hardware · heuristic · karate · 3.15 sQuantum hardware · heuristic · farm · 3.41 sQuantum hardware · heuristic · johnson16-2-4 · 3.52 sQuantum hardware · heuristic · football · 4.91 sQuantum hardware · heuristic · sloane_2dc_128 · 6.85 sQuantum hardware · heuristic · c-fat200-1 · 7.49 sQuantum hardware · heuristic · es60fst01 · 7.87 sQuantum hardware · heuristic · ibm32 · 9.57 sQuantum hardware · heuristic · chesapeake · 14.3 sQuantum hardware · heuristic · es60fst03 · 26.9 sQuantum hardware · heuristic · sloane_1dc_64 · 32.7 sQuantum hardware · heuristic · insecta-ant-colony1-day38 · 37.7 sQuantum hardware · heuristic · hamming6-4 · 57.3 sQuantum hardware · heuristic · MANN-a9 · 68.1 sQuantum hardware · heuristic · mammalia-kangaroo-interactions · 87 sQuantum hardware · heuristic · hamming6-2 · 133 sQuantum hardware · heuristic · johnson8-4-4 · 145.7 sQuantum hardware · heuristic · gen200_p0-9_44 · 199.6 sQuantum hardware · heuristic · aves-sparrow-social · 252 s

Time-to-solution (TTS) to reach best-known objective

Same as the runtime cactus but uses the reported Time-to-Solution rather than total runtime. Solid = exact, dashed = heuristic.

Classical (42 · 28 exact, 14 heuristic) Quantum hardware (12 · heuristic)
Cactus plot: cumulative number of instances solved (horizontal) versus time-to-solution in seconds on a log scale (vertical), one line per method group; lower-right is better.0.010.11101001,000071421283542instances solved →time-to-solution (s, log)Classical · exact · farm · 0 sClassical · exact · mammalia-kangaroo-interactions · 0 sClassical · exact · johnson8-2-4 · 0 sClassical · exact · ibm32 · 0 sClassical · exact · football · 0 sClassical · exact · MANN-a9 · 0 sClassical · exact · insecta-ant-colony1-day38 · 0 sClassical · exact · hamming6-2 · 0 sClassical · exact · hamming6-4 · 0 sClassical · exact · sloane_1dc_64 · 0 sClassical · exact · johnson8-4-4 · 0 sClassical · exact · es60fst03 · 0 sClassical · exact · johnson16-2-4 · 0 sClassical · exact · es60fst01 · 0 sClassical · exact · C125-9 · 0 sClassical · exact · sloane_1dc_128 · 0 sClassical · exact · sloane_1zc_128 · 0 sClassical · exact · sloane_2dc_128 · 0 sClassical · exact · insecta-ant-colony3-day09 · 0 sClassical · exact · es60fst04 · 0 sClassical · exact · keller4 · 0 sClassical · exact · es60fst02 · 0 sClassical · exact · brock200-1 · 0 sClassical · exact · brock200-3 · 0 sClassical · exact · brock200-4 · 0 sClassical · exact · c-fat200-1 · 0 sClassical · exact · gen200_p0-9_44 · 0 sClassical · heuristic · chesapeake · 0.01 sClassical · exact · karate · 0.01 sClassical · heuristic · aves-sparrow-social · 0.01 sClassical · heuristic · brock200-2 · 0.02 sClassical · heuristic · hamming10-4 · 0.1 sClassical · heuristic · p_hat1500-3 · 0.17 sClassical · heuristic · socfb-haverford76 · 0.67 sClassical · heuristic · p_hat1500-1 · 2.45 sClassical · heuristic · C500-9 · 7.51 sClassical · heuristic · brock400-1 · 8.45 sClassical · heuristic · C4000-5 · 167 sClassical · heuristic · keller6 · 291 sClassical · heuristic · brock800-1 · 1,139 sClassical · heuristic · socfb-trinity100 · 1,362 sClassical · heuristic · sorrell4 · 1,709 sQuantum hardware · heuristic · sloane_1dc_128 · 39.1 sQuantum hardware · heuristic · sloane_2dc_128 · 42.3 sQuantum hardware · heuristic · sloane_1zc_128 · 52.9 sQuantum hardware · heuristic · farm · 98 sQuantum hardware · heuristic · mammalia-kangaroo-interactions · 118.8 sQuantum hardware · heuristic · es60fst04 · 121.9 sQuantum hardware · heuristic · es60fst02 · 131.1 sQuantum hardware · heuristic · es60fst03 · 215.5 sQuantum hardware · heuristic · aves-sparrow-social · 725.8 sQuantum hardware · heuristic · MANN-a9 · 807.4 sQuantum hardware · heuristic · es60fst01 · 853 sQuantum hardware · heuristic · insecta-ant-colony1-day38 · 887.9 s

Solution quality (performance profile)

Share of instances each group brings within a given optimality gap of the best-known objective. Higher is better; the value at “best” is the share solved exactly.

Classical (50) Quantum simulator (3) Quantum hardware (28)
Performance profile: share of instances (vertical) reached within a given optimality gap of the best-known objective (horizontal), one line per method group; higher is better.0%25%50%75%100%best+2.8%+13%+52%+200%optimality gap from best-known →instances solved (%)Classical · within best · 100% · farm, mammalia-kangaroo-interactions, johnson8-2-4, ibm32, karate, football, chesapeake, MANN-a9, aves-sparrow-social, insecta-ant-colony1-day38, hamming6-2, hamming6-4, sloane_1dc_64, johnson8-4-4, es60fst03, johnson16-2-4, es60fst01, C125-9, sloane_1dc_128, sloane_1zc_128, sloane_2dc_128, insecta-ant-colony3-day09, es60fst04, keller4, es60fst02, brock200-1, brock200-2, brock200-3, brock200-4, c-fat200-1, gen200_p0-9_44, brock400-1, C500-9, R_500_005_1, brock800-1, frb45-21-3, R_1000_005_1, hamming10-4, frb50-23-3, frb53-24-1, socfb-haverford76, p_hat1500-1, p_hat1500-3, frb59-26-2, sorrell4, sorrell7, socfb-trinity100, keller6, C4000-5, frb100-40Quantum simulator · within best · 2% · es60fst02Quantum simulator · within +180% · 4% · karateQuantum simulator · within +200% · 6% · farmQuantum hardware · within best · 48% · farm, mammalia-kangaroo-interactions, ibm32, karate, football, chesapeake, MANN-a9, aves-sparrow-social, insecta-ant-colony1-day38, hamming6-2, hamming6-4, sloane_1dc_64, johnson8-4-4, es60fst03, johnson16-2-4, es60fst01, C125-9, sloane_1dc_128, sloane_1zc_128, sloane_2dc_128, es60fst04, es60fst02, c-fat200-1, gen200_p0-9_44Quantum hardware · within +11% · 50% · insecta-ant-colony3-day09Quantum hardware · within +25% · 52% · brock200-2Quantum hardware · within +27% · 54% · keller4Quantum hardware · within +57% · 56% · johnson8-2-4

Runtime scaling with instance size

Fastest feasible runtime (log scale) per instance versus Nodes — shows how each group scales.

Classical (50) Quantum simulator (3) Quantum hardware (28)
Scaling plot: fastest feasible runtime in seconds on a log scale (vertical) versus Nodes (horizontal), one series per method group.00.010.11101001,000101001,000Nodes (log) →runtime (s, log)Classical · farm · Nodes 17 · 4.0e-4 sClassical · mammalia-kangaroo-interactions · Nodes 17 · 0 sClassical · johnson8-2-4 · Nodes 28 · 3.0e-4 sClassical · ibm32 · Nodes 32 · 3.0e-4 sClassical · karate · Nodes 34 · 3.0e-4 sClassical · football · Nodes 35 · 0 sClassical · chesapeake · Nodes 39 · 3.0e-4 sClassical · MANN-a9 · Nodes 45 · 6.0e-4 sClassical · aves-sparrow-social · Nodes 52 · 3.0e-4 sClassical · insecta-ant-colony1-day38 · Nodes 56 · 4.0e-4 sClassical · hamming6-2 · Nodes 64 · 4.0e-4 sClassical · hamming6-4 · Nodes 64 · 4.0e-4 sClassical · sloane_1dc_64 · Nodes 64 · 4.0e-4 sClassical · johnson8-4-4 · Nodes 70 · 4.0e-4 sClassical · es60fst03 · Nodes 113 · 4.0e-4 sClassical · johnson16-2-4 · Nodes 120 · 7.0e-4 sClassical · es60fst01 · Nodes 123 · 4.0e-4 sClassical · C125-9 · Nodes 125 · 4.0e-4 sClassical · sloane_1dc_128 · Nodes 128 · 5.0e-4 sClassical · sloane_1zc_128 · Nodes 128 · 5.0e-4 sClassical · sloane_2dc_128 · Nodes 128 · 0 sClassical · insecta-ant-colony3-day09 · Nodes 160 · 8.0e-4 sClassical · es60fst04 · Nodes 162 · 0 sClassical · keller4 · Nodes 171 · 8.0e-4 sClassical · es60fst02 · Nodes 186 · 6.0e-4 sClassical · brock200-1 · Nodes 200 · 0 sClassical · brock200-2 · Nodes 200 · 0 sClassical · brock200-3 · Nodes 200 · 9.0e-4 sClassical · brock200-4 · Nodes 200 · 0 sClassical · c-fat200-1 · Nodes 200 · 4.0e-4 sClassical · gen200_p0-9_44 · Nodes 200 · 9.0e-4 sClassical · brock400-1 · Nodes 400 · 1.09 sClassical · C500-9 · Nodes 500 · 1.13 sClassical · R_500_005_1 · Nodes 500 · 1.25 sClassical · brock800-1 · Nodes 800 · 1.27 sClassical · frb45-21-3 · Nodes 945 · 1.39 sClassical · R_1000_005_1 · Nodes 1,000 · 1.51 sClassical · hamming10-4 · Nodes 1,024 · 1.43 sClassical · frb50-23-3 · Nodes 1,150 · 1.62 sClassical · frb53-24-1 · Nodes 1,272 · 1.94 sClassical · socfb-haverford76 · Nodes 1,446 · 5.01 sClassical · p_hat1500-1 · Nodes 1,500 · 2.49 sClassical · p_hat1500-3 · Nodes 1,500 · 0.19 sClassical · frb59-26-2 · Nodes 1,534 · 3.31 sClassical · sorrell4 · Nodes 2,048 · 5.06 sClassical · sorrell7 · Nodes 2,048 · 5.26 sClassical · socfb-trinity100 · Nodes 2,613 · 5.02 sClassical · keller6 · Nodes 3,361 · 12.5 sClassical · C4000-5 · Nodes 4,000 · 12.3 sClassical · frb100-40 · Nodes 4,000 · 5.06 sQuantum simulator · farm · Nodes 17 · 0.4 sQuantum simulator · karate · Nodes 34 · 0.6 sQuantum simulator · es60fst02 · Nodes 186 · 61.3 sQuantum hardware · farm · Nodes 17 · 3.41 sQuantum hardware · mammalia-kangaroo-interactions · Nodes 17 · 87 sQuantum hardware · johnson8-2-4 · Nodes 28 · 16.3 sQuantum hardware · ibm32 · Nodes 32 · 9.57 sQuantum hardware · karate · Nodes 34 · 3.15 sQuantum hardware · football · Nodes 35 · 4.91 sQuantum hardware · chesapeake · Nodes 39 · 14.3 sQuantum hardware · MANN-a9 · Nodes 45 · 68.1 sQuantum hardware · aves-sparrow-social · Nodes 52 · 252 sQuantum hardware · insecta-ant-colony1-day38 · Nodes 56 · 37.7 sQuantum hardware · hamming6-2 · Nodes 64 · 133 sQuantum hardware · hamming6-4 · Nodes 64 · 57.3 sQuantum hardware · sloane_1dc_64 · Nodes 64 · 32.7 sQuantum hardware · johnson8-4-4 · Nodes 70 · 145.7 sQuantum hardware · es60fst03 · Nodes 113 · 26.9 sQuantum hardware · johnson16-2-4 · Nodes 120 · 3.52 sQuantum hardware · es60fst01 · Nodes 123 · 7.87 sQuantum hardware · C125-9 · Nodes 125 · 2.94 sQuantum hardware · sloane_1dc_128 · Nodes 128 · 2.18 sQuantum hardware · sloane_1zc_128 · Nodes 128 · 2.39 sQuantum hardware · sloane_2dc_128 · Nodes 128 · 6.85 sQuantum hardware · insecta-ant-colony3-day09 · Nodes 160 · 388.2 sQuantum hardware · es60fst04 · Nodes 162 · 2.46 sQuantum hardware · keller4 · Nodes 171 · 524.1 sQuantum hardware · es60fst02 · Nodes 186 · 2.56 sQuantum hardware · brock200-2 · Nodes 200 · 1,033 sQuantum hardware · c-fat200-1 · Nodes 200 · 7.49 sQuantum hardware · gen200_p0-9_44 · Nodes 200 · 199.6 s

Submissions (16)

Method Submitter Type Date Instances
Quicopt Tim Bode Classical 2026-08-13 50
ParallelILS Narendra N. Hegade Classical 2026-08-06 50
HSQC Narendra N. Hegade Quantum HW 20260804 6
Parity_Twine ParityQC Team Quantum HW 2026-07-30 6
Aqarios David Bucher Quantum HW 2026-07-11 5
SA Q-Bridge Team Classical 2026-07-09 4
20260709_JIJ Keisuke Sato, Hiromichi Matsuyama, Yuichiro Nakano, Kohji Nishimura, Yu Yamashiro Quantum HW 2026-07-09 26
Qunova Jeung Rac Lee Quantum HW 20260630 5
QctrlSolver Kara Maller Quantum HW 2026-06-24 2
QAOA_AerMPS Alejandro Montanez Quantum sim 2026-06-11 1
Arvak Daniel Hinderink Quantum sim 2026-03-08 3
QAOA_ibm_boston Alejandro Montanez Quantum HW 2025-11-27 1
MIP Maximilian Schicker Classical 2025-07-15 50
Abs2 Maximilian Schicker Classical 2025-07-15 50
Quicopt Tim Bode Classical 20250627 6
QAOA Daniel Egger Quantum HW 2025-01-15 2

Instances (50)

50 of 50
Name Nodes Edges Best objective Source Status Download
aves-sparrow-social 52 454 13 Reference solution Optimal ↓ raw
brock200-1 200 14,834 6 Reference solution Optimal ↓ raw
brock200-2 200 10,024 12 Reference solution Optimal ↓ raw
brock200-3 200 12,048 9 Reference solution Optimal ↓ raw
brock200-4 200 13,089 8 Reference solution Optimal ↓ raw
brock400-1 400 20,077 27 Reference solution Optimal ↓ raw
brock800-1 800 112,095 23 Reference solution Optimal ↓ raw
C125-9 125 787 34 Reference solution Optimal ↓ raw
C500-9 500 12,418 57 Reference solution Best known ↓ raw
C4000-5 4,000 3,997,732 18 Reference solution Best known ↓ raw
c-fat200-1 200 1,534 18 Reference solution Optimal ↓ raw
chesapeake 39 170 17 Reference solution Optimal ↓ raw
es60fst01 123 159 60 Reference solution Optimal ↓ raw
es60fst02 186 280 88 Reference solution Optimal ↓ raw
es60fst03 113 142 55 Reference solution Optimal ↓ raw
es60fst04 162 238 78 Reference solution Optimal ↓ raw
farm 17 39 10 Reference solution Optimal ↓ raw
football 35 118 16 Reference solution Optimal ↓ raw
frb45-21-3 945 58,245 45 Reference solution Optimal ↓ raw
frb50-23-3 1,150 81,068 50 Reference solution Optimal ↓ raw
frb53-24-1 1,272 94,227 53 Reference solution Best known ↓ raw
frb59-26-2 1,534 126,163 58 Reference solution Best known ↓ raw
frb100-40 4,000 572,774 96 Reference solution Best known ↓ raw
gen200_p0-9_44 200 1,990 44 Reference solution Optimal ↓ raw
hamming6-2 64 1,824 2 Reference solution Optimal ↓ raw
hamming6-4 64 704 12 Reference solution Optimal ↓ raw
hamming10-4 1,024 89,600 40 Reference solution Best known ↓ raw
ibm32 32 90 13 Reference solution Optimal ↓ raw
insecta-ant-colony1-day38 56 1,134 6 Reference solution Optimal ↓ raw
insecta-ant-colony3-day09 160 8,883 9 Reference solution Optimal ↓ raw
johnson8-2-4 28 210 7 Reference solution Optimal ↓ raw
johnson8-4-4 70 1,855 5 Reference solution Optimal ↓ raw
johnson16-2-4 120 5,460 15 Reference solution Optimal ↓ raw
karate 34 78 20 Reference solution Optimal ↓ raw
keller4 171 5,100 11 Reference solution Optimal ↓ raw
keller6 3,361 1,026,582 59 Reference solution Best known ↓ raw
mammalia-kangaroo-interactions 17 91 4 Reference solution Optimal ↓ raw
MANN-a9 45 918 3 Reference solution Optimal ↓ raw
p_hat1500-1 1,500 839,327 12 Reference solution Optimal ↓ raw
p_hat1500-3 1,500 277,006 94 Reference solution Optimal ↓ raw
R_500_005_1 500 6,256 91 Reference solution Best known ↓ raw
R_1000_005_1 1,000 24,670 117 Reference solution Best known ↓ raw
sloane_1dc_64 64 543 10 Reference solution Optimal ↓ raw
sloane_1dc_128 128 1,471 16 Reference solution Optimal ↓ raw
sloane_1zc_128 128 1,120 18 Reference solution Optimal ↓ raw
sloane_2dc_128 128 5,173 5 Reference solution Optimal ↓ raw
socfb-haverford76 1,446 59,589 282 Reference solution Optimal ↓ raw
socfb-trinity100 2,613 111,996 499 Reference solution Best known ↓ raw
sorrell4 2,048 504,451 24 Reference solution Optimal ↓ raw
sorrell7 2,048 39,424 198 Reference solution Best known ↓ raw