\"\"This is for Data Structures Bit Manipulation Lab \"\" ( C programming with \
ID: 3664442 • Letter: #
Question
""This is for Data Structures Bit Manipulation Lab "" ( C programming with """"only"""" #include <limits.h>)
/*
* bang - Compute !x without using !
* Examples: bang(3) = 0, bang(0) = 1
* Legal ops: ~ & ^ | + << >>
* Max ops: 12
* Rating: 4
*/
int bang(int x) {
return 2;
}
Please include descriptive explation of steps to the code. I really want to understand how it works. I've already spent too much time trying to solve this problem with no luck.
And not understanding it at this point would be very frustrating.
Explanation / Answer
int bang ( int x)
{
// the logical negative value of x.
int negative_x = ~x + 1;
// If ( x != 0), then the most significant bit ( or sign bit ) of either x or -x will be 1.
// XOR the sign bit of x or -x with the mask 0x01 to reproduce functionality of !
return ( ( ( ( x > > 31 ) & 0x01) / ( ( negative_x > > 31) & 0x01 ) ) ^ 0x01 ) ;
}
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