Reverse Bits

Reverse bits of a given 32 bits unsigned integer.

For example, given input 43261596 (represented in binary as 00000010100101000001111010011100), return 964176192 (represented in binary as 00111001011110000010100101000000).

Follow up: If this function is called many times, how would you optimize it?

Related problem: Reverse Integer

Solution

    uint32_t reverseBits(uint32_t n) {
        uint32_t result = 0;
        for (int i=0; i<32; i++) {
            result = (result << 1) + (n >> i & 1);
        }        
        return result;
    }