Integer Performance Comparison for C++, C#, Delphi
In this post, I have compared three versions (from the same codebase) using Delphi to count the number of primes between 1 to N. Actually, this is quite a …
Category: integer
Simple C++ Coding Exercise – Use Lookup Table to Eliminate the Condition Checks
There is a popular IQ question, e.g. according to the first few number patterns, find the answer to the input: 1234 = 0 4567 = 1 2345 = 0 …
C++ Coding Example, Using Hash Algorithm to Remove Duplicate Number by O(n)
Hashing is an important technique in Computer Science. There are many cases that you can use Hash to speed up your algorithms (e.g. by reducing from O(n^2) to O(n) …
How Many One’s Between Number 1 to N ?
Question: Given a positive integer (nature number) N, count the number of ‘1’s between number 1 to N inclusive. For example, when N = 2, the answer is 1, …
Fast Power of Two Equal or Larger than a 32-bit Integer
I have seen a naive implementation at work today (written by a colleague). My colleague intends to generate a number that is power of two, and the number is …