Write a program to swap odd and even bits in an integer with as few instructions as possible (e.g., bit 0 and bit 1 are swapped, bit 2 and bit 3 are swapped, and so on).
Example1:
Input: num = 2（0b10） Output 1 (0b01)
Example2:
Input: num = 3 Output: 3
Note:
0 <= num <=2^30 - 1- The result integer fits into 32-bit integer.
class Solution {
public int exchangeBits(int num) {
int t1 = num >> 1;
int t2 = num << 1;
return t1 & 0x55555555 | t2 & 0xaaaaaaaa;
}
}