For integer variable x! The value of x is nothing more than 0 or 1-the result is 0 if and only if x is equal to 0, otherwise the result is1.

Do it again! After the operation, the original 0 result will be 1, and the original 1 corresponds to 0.

So! (! The value of x) is-the result is 0 if and only if x is equal to 0, otherwise it is 1. (that is, to determine whether a number is non-zero, and x! The values of =0 are consistent. )

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