【leetcode】颠倒二进制位

uint32_t reverseBits(uint32_t n) {
    int arr[32] = {0};
    int i=0;
    while(n)
    {
        arr[i++] = n % 2;
        n /= 2;
    }
    for(i=0; i<32; i++)
    {
        n += (arr[i])? pow(2,32-1-i): 0;
    }
    return n;
}