Bit Manipulation & Low-Level Computing

In low-level systems programming and coding interviews, people always use the expression n & (n - 1) to count set bits (Hamming Weight) or check if a number is a power of 2. I know it works, but what is the ...Read more

When elements in an array appear twice except one, we can simply XOR all numbers together. But what if every element appears three times, except for a single number that appears once? The standard hash-map solution uses O(N) space. How can ...Read more