Divide and Conquer Networks

Alex Nowak, David Folqué, Joan Bruna

Abstract:

We consider the learning of algorithmic tasks by mere observation of input-output
pairs. Rather than studying this as a black-box discrete regression problem with
no assumption whatsoever on the input-output mapping, we concentrate on tasks
that are amenable to the principle of divide and conquer, and study what are its
implications in terms of learning.
This principle creates a powerful inductive bias that we leverage with neural
architectures that are defined recursively and dynamically, by learning two scale-
invariant atomic operations: how to split a given input into smaller sets, and how
to merge two partially solved tasks into a larger partial solution. Our model can be
trained in weakly supervised environments, namely by just observing input-output
pairs, and in even weaker environments, using a non-differentiable reward signal.
Moreover, thanks to the dynamic aspect of our architecture, we can incorporate
the computational complexity as a regularization term that can be optimized by
backpropagation. We demonstrate the flexibility and efficiency of the Divide-
and-Conquer Network on several combinatorial and geometric tasks: convex hull,
clustering, knapsack and euclidean TSP. Thanks to the dynamic programming
nature of our model, we show significant improvements in terms of generalization
error and computational complexity.

TL;DR: Dynamic model that learns divide and conquer strategies by weak supervision.

Keywords: Neural Networks, Combinatorial Optimization, Algorithms

Code: [ alexnowakvila/DiCoNet](https://github.com/alexnowakvila/DiCoNet)

Community Implementations: [ 1 code implementation](https://www.catalyzex.com/paper/divide-and-conquer-networks/code)