# Given a directed graph $G$, how to find a subgraph $G'$, where every node in $G'$ is isolated and the size of $G'$ is largest possible? [closed]

Given a directed graph $$G$$, how to find a subgraph $$G'$$, where every node in $$G'$$ is isolated and the size of $$G'$$ is largest possible ?

## closed as off-topic by Max Alekseyev, user44191, Chris Godsil, Wolfgang, darij grinbergMay 15 at 7:22

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• Isn't that the independence number problem? – Bullet51 May 11 at 3:11