In Nature Machine Intelligence 4, 367 (2022), Schuetz et al provide a scheme to employ graph neural networks (GNN) as a heuristic to solve a variety of classical, NP-hard combinatorial optimization problems. It describes how the network is trained on sample instances and the resulting GNN heuristic is evaluated applying widely used techniques to determine its ability to succeed. Clearly, the idea of harnessing the powerful abilities of such networks to ``learn'' the intricacies of complex, multimodal energy landscapes in such a hands-off approach seems enticing. And based on the observed performance, the heuristic promises to be highly scalable, with a computational cost linear in the input size $n$, although there is likely a significant overhead in the pre-factor due to the GNN itself. However, closer inspection shows that the reported results for this GNN are only minutely better than those for gradient descent and get outperformed by a greedy algorithm, for example, for Max-Cut. The discussion also highlights what I believe are some common misconceptions in the evaluations of heuristics.

Schuetz等人提出了一种使用图神经网络作为启发式方法来解决各种组合优化问题的方案，该方法通过样例实例对网络进行训练，并应用广泛使用的技术来评估其成功的能力，尽管报告的结果只比梯度下降略有改善，但该方法承诺具有高度可伸缩性和计算成本线性。

图神经网络启发式算法无法在解决如Max-Cut等组合优化问题中超越贪婪算法