A/C + + Shift operation makes the value of an expression the same as the nth bit of a variable

1, problem description

There are two int variables A and n require that an expression be written so that the value of the expression is the same as the nth bit of a

2, not comprehensive implementation

In the microcontroller program is often seen in the implementation is

(A & (1 << N)) >> n

However, it is important to note that the implementation when n is 31, if it is a negative number, then the sign bit is 1, the right shift 31 bit after the result is not 1!

3. Correct solution

1

This method is established in the case of 0 <= N <= 31.

A/C + + Shift operation makes the value of an expression the same as the nth bit of a variable