Determining the sign of an int using shifts? [closed]

Question

Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.

---

Questions asking for code must demonstrate a minimal understanding of the problem being solved. Include attempted solutions, why they didn't work, and the expected results. See also: Stack Overflow question checklist

Closed 8 years ago.

Improve this question

Here's the question

• sign - return 1 if positive, 0 if zero, and -1 if negative
• Legal ops: ! ~ & ^ | + << >>
• Max ops: 10
• Rating: 2

I thought of shifting to the right by 31 to grab the sign bit but can't 0 be positive AND negative technically?

Answer 1

You may try like this for 32 bit int:-

(x >> 31) | (((~x + 1) >> 31) & 1)