Swap odd bits and even bits

Solution

#include <iostream>

using namespace std;

unsigned int swap_bits(int a)

{

unsigned int b = a;

unsigned int c = b & 0xAAAAAAAA;

unsigned int d = b & 0x55555555;

c >>= 1;

d <<= 1;

return (unsigned int)( c | d);

}

int main(int argc, char* argv[])

{

cout.unsetf(ios::dec);

cout.setf(ios::hex);

cout.setf(ios::showbase);

unsigned int a = 0xAAAA;

cout << a << endl;

cout << swap_bits(a) << endl;

return 0;

}