# NP-completeness #computer-science A problem is said to be [NP-hard](https://en.wikipedia.org/wiki/NP-hard) if everything in NP can be transformed in polynomial time into it, and a problem is NP-complete if it is both in NP and NP-hard. 📖 [NP-completeness - Wikipedia](https://en.wikipedia.org/wiki/NP-completeness)