[minor3rd]

I haven't used bitwise operators since college (approaching 8 years ago) but wanted to try this as a fun exercise during the NFL playoff game. Here's what I came up with -- mostly untested.

[edit] Note this is obviously for 16-bit integers.

int flip_endian_helper(int num, int i) {

    if (i == 16) {
     return 0;
    }

    int shift = 15 - 2*i;
    int workingBit = num & (1 << i);
    int partial = shift > 0 ? workingBit << shift : workingBit >> (shift * (-1));
    
    return partial | flip_endian(num, i + 1);

}

int flip_endian(int num) {

  return flip_endian_helper(num, 0);

}