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A problem is in P if it can be solved quickly by a computer, and in NP if a solution can be verified quickly.
一个问题如果在计算机上可以快速解决,那么它属于P类问题;如果一个解可以快速验证,那么它属于NP类问题。
可持续发展不是一种选择;它是能源未来的必要条件。
If you hate yourself, you will hate others. If you cannot love yourself, you cannot love others.